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<body>
<div class="head">
<p>
<a href="http://www.w3.org/">
<img width="72" height="48" src="http://www.w3.org/Icons/w3c_home" alt="W3C" />
</a>
</p>
<h1 class="title" id="title">
JSON-LD
Syntax
1.0
</h1>
<h2 id="subtitle">
A
Context-based
JSON
Serialization
for
Linking
Data
</h2>
<h2 id="w3c-editor-s-draft-30-september-2012">
<abbr title="World Wide Web Consortium">
W3C
<del class="diff-old">Working
</del>
</abbr>
<ins class="diff-chg">Editor's
</ins>
Draft
<del class="diff-old">12
July
</del>
<ins class="diff-chg">30
September
</ins>
2012
</h2>
<dl>
<dt>
This
version:
</dt>
<dd>
<del class="diff-old">http://www.w3.org/TR/2012/WD-json-ld-syntax-20120712/
</del>
<a href="http://dvcs.w3.org/hg/json-ld/raw-file/default/spec/latest/json-ld-syntax/index.html">
<ins class="diff-chg">http://dvcs.w3.org/hg/json-ld/raw-file/default/spec/latest/json-ld-syntax/index.html
</ins>
</a>
</dd>
<dt>
Latest
published
version:
</dt>
<dd>
<a href="http://www.w3.org/TR/json-ld-syntax/">
http://www.w3.org/TR/json-ld-syntax/
</a>
</dd>
<dt>
Latest
editor's
draft:
</dt>
<dd>
<a href="http://dvcs.w3.org/hg/json-ld/raw-file/default/spec/latest/json-ld-syntax/index.html">
http://dvcs.w3.org/hg/json-ld/raw-file/default/spec/latest/json-ld-syntax/index.html
</a>
</dd>
<dt>
Editors:
</dt>
<dd rel="bibo:editor" inlist="">
<span typeof="foaf:Person">
<a rel="foaf:homepage" property="foaf:name" content="Manu Sporny" href="http://manu.sporny.org/">
Manu
Sporny
</a>,
<a rel="foaf:workplaceHomepage" href="http://digitalbazaar.com/">
Digital
Bazaar
</a>
</span>
</dd>
<dd rel="bibo:editor" inlist="">
<span typeof="foaf:Person">
<a rel="foaf:homepage" property="foaf:name" content="Gregg Kellogg" href="http://greggkellogg.net/">
Gregg
Kellogg
</a>,
<a rel="foaf:workplaceHomepage" href="http://kellogg-assoc.com/">
Kellogg
Associates
</a>
</span>
</dd>
<dd rel="bibo:editor" inlist="">
<span typeof="foaf:Person">
<a rel="foaf:homepage" property="foaf:name" content="Markus Lanthaler" href="http://www.markus-lanthaler.com/">
Markus
Lanthaler
</a>,
<a rel="foaf:workplaceHomepage" href="http://www.tugraz.at/">
Graz
University
of
Technology
</a>
</span>
</dd>
<dt>
Authors:
</dt>
<dd rel="dcterms:contributor">
<span typeof="foaf:Person">
<a rel="foaf:homepage" property="foaf:name" content="Manu Sporny" href="http://digitalbazaar.com/">
Manu
Sporny
</a>,
<a rel="foaf:workplaceHomepage" href="http://digitalbazaar.com/">
Digital
Bazaar
</a>
</span>
</dd>
<dd rel="dcterms:contributor">
<span typeof="foaf:Person">
<a rel="foaf:homepage" property="foaf:name" content="Dave Longley" href="http://digitalbazaar.com/">
Dave
Longley
</a>,
<a rel="foaf:workplaceHomepage" href="http://digitalbazaar.com/">
Digital
Bazaar
</a>
</span>
</dd>
<dd rel="dcterms:contributor">
<span typeof="foaf:Person">
<a rel="foaf:homepage" property="foaf:name" content="Gregg Kellogg" href="http://greggkellogg.net/">
Gregg
Kellogg
</a>,
<a rel="foaf:workplaceHomepage" href="http://kellogg-assoc.com/">
Kellogg
Associates
</a>
</span>
</dd>
<dd rel="dcterms:contributor">
<span typeof="foaf:Person">
<a rel="foaf:homepage" property="foaf:name" content="Markus Lanthaler" href="http://www.markus-lanthaler.com/">
Markus
Lanthaler
</a>,
<a rel="foaf:workplaceHomepage" href="http://www.tugraz.at/">
Graz
University
of
Technology
</a>
</span>
</dd>
<dd rel="dcterms:contributor">
<span typeof="foaf:Person">
<a rel="foaf:homepage" property="foaf:name" content="Mark Birbeck" href="http://webbackplane.com/">
Mark
Birbeck
</a>,
<del class="diff-old">Sidewinder
Labs
</del>
<a rel="foaf:workplaceHomepage" href="http://webbackplane.com/">
<ins class="diff-chg">Backplane
Ltd.
</ins></a>
</span>
</dd>
</dl>
<p>
This
document
is
also
available
in
this
non-normative
format:
<a href="diff-20120712.html">
diff
to
previous
version
</a>
</p>
<p class="copyright">
<a href="http://www.w3.org/Consortium/Legal/ipr-notice#Copyright">
Copyright
</a>
©
2010-2012
<a href="http://www.w3.org/">
<abbr title="World Wide Web Consortium">
W3C
</abbr>
</a>
<sup>
®
</sup>
(
<a href="http://www.csail.mit.edu/">
<abbr title="Massachusetts Institute of Technology">
MIT
</abbr>
</a>,
<a href="http://www.ercim.eu/">
<abbr title="European Research Consortium for Informatics and Mathematics">
ERCIM
</abbr>
</a>,
<a href="http://www.keio.ac.jp/">
Keio
</a>
),
All
Rights
Reserved.
<abbr title="World Wide Web Consortium">
W3C
</abbr>
<a href="http://www.w3.org/Consortium/Legal/ipr-notice#Legal_Disclaimer">
liability
</a>,
<a href="http://www.w3.org/Consortium/Legal/ipr-notice#W3C_Trademarks">
trademark
</a>
and
<a href="http://www.w3.org/Consortium/Legal/copyright-documents">
document
use
</a>
rules
apply.
</p>
<hr />
</div>
<section id="abstract" class="introductory">
<h2>
Abstract
</h2>
<p>
JSON
has
proven
to
be
a
highly
useful
object
serialization
and
messaging
format.
In
an
attempt
to
harmonize
the
representation
of
<a class="tref internalDFN" title="linked_data" href="#dfn-linked_data">
Linked
Data
</a>
in
JSON,
this
specification
outlines
a
common
JSON
representation
format
for
expressing
directed
graphs;
mixing
both
Linked
Data
and
non-Linked
Data
in
a
single
document.
</p>
</section>
<section id="sotd" class="introductory">
<h2>
Status
of
This
Document
</h2>
<p>
<em>
This
section
describes
the
status
of
this
document
at
the
time
of
its
publication.
Other
documents
may
supersede
this
document.
A
list
of
current
<abbr title="World Wide Web Consortium">
W3C
</abbr>
publications
and
the
latest
revision
of
this
technical
report
can
be
found
in
the
<a href="http://www.w3.org/TR/">
<abbr title="World Wide Web Consortium">
W3C
</abbr>
technical
reports
index
</a>
at
http://www.w3.org/TR/.
</em>
</p>
<p>
This
document
has
been
under
development
for
over
<del class="diff-old">18
</del>
<ins class="diff-chg">20
</ins>
months
in
the
JSON
for
Linking
Data
Community
Group.
The
document
has
recently
been
transferred
to
the
RDF
Working
Group
for
review,
improvement,
and
publication
along
the
Recommendation
track.
<del class="diff-old">While
this
is
a
First
Public
Working
Draft
publication,
the
</del>
<ins class="diff-chg">The
</ins>
specification
has
undergone
significant
development,
review,
and
changes
during
the
course
of
the
last
<del class="diff-old">18
months
and
is
more
mature
than
the
First
Public
Working
Draft
status
implies.
</del>
<ins class="diff-chg">20
months.
</ins>
</p>
<p>
There
are
currently
<a href="http://json-ld.org/#impl">
five
interoperable
implementations
</a>
of
this
specification.
There
is
a
<a href="https://github.com/json-ld/json-ld.org/tree/main/test-suite">
fairly
complete
test
suite
</a>
and
a
<a href="http://json-ld.org/playground/">
live
JSON-LD
editor
</a>
that
is
capable
of
demonstrating
the
features
described
in
this
document.
While
development
on
implementations,
the
test
suite
and
the
live
editor
will
continue,
they
are
believed
to
be
mature
enough
to
be
integrated
into
a
non-production
system
at
this
point
in
time
with
the
expectation
that
they
could
be
used
in
a
production
system
within
the
next
year.
</p>
<p>
There
are
a
number
of
ways
that
one
may
participate
in
the
development
of
this
specification:
</p>
<ul>
<li>
If
you
want
to
make
sure
that
your
feedback
is
formally
addressed
by
the
RDF
Working
Group,
you
should
send
it
to
public-rdf-comments:
<a href="http://lists.w3.org/Archives/Public/public-rdf-comments/">
public-rdf-comments@w3.org
</a>
</li>
<li>
Ad-hoc
technical
discussion
primarily
occurs
on
the
public
community
mailing
list:
<a href="http://lists.w3.org/Archives/Public/public-linked-json/">
public-linked-json@w3.org
</a>
</li>
<li>
<a href="http://json-ld.org/minutes/">
Public
JSON-LD
Community
Group
teleconferences
</a>
are
held
on
Tuesdays
at
1500UTC
every
week.
</li>
<li>
RDF
Working
Group
teleconferences
are
held
on
Wednesdays
at
1500UTC
every
week.
Participation
is
limited
to
RDF
Working
Group
members.
</li>
<li>
Specification
bugs
and
issues
should
be
reported
in
the
<a href="https://github.com/json-ld/json-ld.org/issues">
issue
tracker
</a>
if
you
do
not
want
to
send
an
e-mail
to
the
public-rdf-comments
mailing
list.
</li>
<li>
<a href="https://github.com/json-ld/json-ld.org/tree/main/spec">
Source
code
</a>
for
the
specification
can
be
found
on
Github.
</li>
<li>
The
<a href="http://webchat.freenode.net/?channels=json-ld">
#json-ld
</a>
IRC
channel
is
available
for
real-time
discussion
on
irc.freenode.net.
</li>
</ul>
<p>
This
document
was
published
by
the
<a href="http://www.w3.org/2011/rdf-wg/">
RDF
Working
Group
</a>
as
<del class="diff-old">a
First
Public
Working
</del>
<ins class="diff-chg">an
Editor's
</ins>
Draft.
<del class="diff-old">This
document
is
intended
to
become
a
W3C
Recommendation.
</del>
If
you
wish
to
make
comments
regarding
this
document,
please
send
them
to
<a href="mailto:public-rdf-comments@w3.org">
public-rdf-comments@w3.org
</a>
(
<a href="mailto:public-rdf-comments-request@w3.org?subject=subscribe">
subscribe
</a>,
<a href="http://lists.w3.org/Archives/Public/public-rdf-comments/">
archives
</a>
).
All
feedback
is
welcome.
</p>
<p>
Publication
as
<del class="diff-old">a
Working
</del>
<ins class="diff-chg">an
Editor's
</ins>
Draft
does
not
imply
endorsement
by
the
<abbr title="World Wide Web Consortium">
W3C
</abbr>
Membership.
This
is
a
draft
document
and
may
be
updated,
replaced
or
obsoleted
by
other
documents
at
any
time.
It
is
inappropriate
to
cite
this
document
as
other
than
work
in
progress.
</p>
<p>
This
document
was
produced
by
a
group
operating
under
the
<a href="http://www.w3.org/Consortium/Patent-Policy-20040205/">
5
February
2004
<abbr title="World Wide Web Consortium">
W3C
</abbr>
Patent
Policy
</a>.
<abbr title="World Wide Web Consortium">
W3C
</abbr>
maintains
a
<a href="http://www.w3.org/2004/01/pp-impl/46168/status" rel="disclosure">
public
list
of
any
patent
disclosures
</a>
made
in
connection
with
the
deliverables
of
the
group;
that
page
also
includes
instructions
for
disclosing
a
patent.
An
individual
who
has
actual
knowledge
of
a
patent
which
the
individual
believes
contains
<a href="http://www.w3.org/Consortium/Patent-Policy-20040205/#def-essential">
Essential
Claim(s)
</a>
must
disclose
the
information
in
accordance
with
<a href="http://www.w3.org/Consortium/Patent-Policy-20040205/#sec-Disclosure">
section
6
of
the
<abbr title="World Wide Web Consortium">
W3C
</abbr>
Patent
Policy
</a>.
</p>
</section>
<section id="toc">
<h2 class="introductory">
Table
of
Contents
</h2>
<ul class="toc">
<li class="tocline">
<a href="#introduction" class="tocxref">
<span class="secno">
1.
</span>
Introduction
</a>
<ul class="toc">
<li class="tocline">
<a href="#how-to-read-this-document" class="tocxref">
<span class="secno">
1.1
</span>
How
to
Read
this
Document
</a>
</li>
</ul>
</li>
<li class="tocline">
<a href="#design-goals-and-rationale" class="tocxref">
<span class="secno">
2.
</span>
Design
Goals
and
Rationale
</a>
</li>
<li class="tocline">
<a href="#basic-concepts" class="tocxref">
<span class="secno">
3.
</span>
Basic
Concepts
</a>
<ul class="toc">
<li class="tocline">
<a href="#benefits-of-json-ld" class="tocxref">
<span class="secno">
3.1
</span>
<del class="diff-old">Linking
</del>
<ins class="diff-chg">Benefits
of
JSON-LD
</ins></a></li><li class="tocline"><a href="#json-ld-data-model" class="tocxref"><span class="secno"><ins class="diff-chg">
3.2
</ins></span><ins class="diff-chg">
JSON-LD
</ins>
Data
<ins class="diff-new">Model
</ins>
</a>
</li>
<li class="tocline">
<a href="#general-terminology" class="tocxref">
<span class="secno">
<ins class="diff-chg">3.3
</ins></span><ins class="diff-chg">
General
Terminology
</ins></a></li>
<li class="tocline">
<a href="#syntax-tokens-and-keywords" class="tocxref">
<span class="secno">
<del class="diff-old">3.1.1
</del>
<ins class="diff-chg">3.4
</ins>
</span>
Syntax
Tokens
and
Keywords
</a>
</li>
<li class="tocline">
<a href="#the-context" class="tocxref">
<span class="secno">
<del class="diff-old">3.1.2
</del>
<ins class="diff-chg">3.5
</ins>
</span>
The
Context
</a>
</li>
<li class="tocline">
<a href="#from-json-to-json-ld" class="tocxref">
<span class="secno">
<del class="diff-old">3.1.3
</del>
<ins class="diff-chg">3.6
</ins>
</span>
From
JSON
to
JSON-LD
</a>
</li>
<li class="tocline">
<a href="#iris" class="tocxref">
<span class="secno">
<del class="diff-old">3.2
</del>
<ins class="diff-chg">3.7
</ins>
</span>
IRIs
</a>
</li>
<li class="tocline">
<a href="#node-identifiers" class="tocxref">
<span class="secno">
<del class="diff-old">3.3
</del>
<ins class="diff-chg">3.8
</ins>
</span>
<del class="diff-old">Identifying
the
Subject
</del>
<ins class="diff-chg">Node
Identifiers
</ins>
</a>
</li>
<li class="tocline">
<a href="#specifying-the-type" class="tocxref">
<span class="secno">
<del class="diff-old">3.4
</del>
<ins class="diff-chg">3.9
</ins>
</span>
Specifying
the
Type
</a>
</li>
<li class="tocline">
<a href="#string-internationalization" class="tocxref">
<span class="secno">
<del class="diff-old">3.5
</del>
<ins class="diff-chg">3.10
</ins>
</span>
String
Internationalization
</a>
</li>
<li class="tocline">
<a href="#json-ld-syntax" class="tocxref">
<span class="secno">
<del class="diff-old">3.6
</del>
<ins class="diff-chg">3.11
</ins>
</span>
JSON-LD
Syntax
</a>
</li>
</ul>
</li>
<li class="tocline">
<a href="#advanced-concepts" class="tocxref">
<span class="secno">
4.
</span>
Advanced
Concepts
</a>
<ul class="toc">
<li class="tocline">
<a href="#compact-iris" class="tocxref">
<span class="secno">
4.1
</span>
Compact
IRIs
</a>
</li>
<li class="tocline">
<a href="#typed-values" class="tocxref">
<span class="secno">
4.2
</span>
Typed
Values
</a>
</li>
<li class="tocline">
<a href="#language-tagged-strings" class="tocxref">
<span class="secno">
4.3
</span>
<del class="diff-old">External
Contexts
</del>
<ins class="diff-chg">Language-tagged
Strings
</ins>
</a>
</li>
<li class="tocline">
<a href="#referencing-contexts-from-json-documents" class="tocxref">
<span class="secno">
4.4
</span>
Referencing
Contexts
from
JSON
Documents
</a>
</li>
<li class="tocline">
<a href="#expanded-term-definition" class="tocxref">
<span class="secno">
4.5
</span>
Expanded
Term
Definition
</a>
</li>
<li class="tocline">
<a href="#type-coercion" class="tocxref">
<span class="secno">
4.6
</span>
Type
Coercion
</a>
</li>
<li class="tocline">
<a href="#property-generators" class="tocxref">
<span class="secno">
4.7
</span>
<ins class="diff-new">Property
Generators
</ins></a></li><li class="tocline"><a href="#iri-expansion-within-a-context" class="tocxref"><span class="secno"><ins class="diff-new">
4.8
</ins></span>
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
Expansion
Within
a
Context
</a>
</li>
<li class="tocline">
<a href="#sets-and-lists" class="tocxref">
<span class="secno">
<del class="diff-old">4.8
</del>
<ins class="diff-chg">4.9
</ins>
</span>
Sets
and
Lists
</a>
</li>
<li class="tocline">
<a href="#embedding" class="tocxref">
<span class="secno">
<del class="diff-old">4.9
</del>
<ins class="diff-chg">4.10
</ins>
</span>
Embedding
</a>
</li>
<li class="tocline">
<a href="#named-graphs" class="tocxref">
<span class="secno">
<del class="diff-old">4.10
</del>
<ins class="diff-chg">4.11
</ins>
</span>
Named
Graphs
</a>
</li>
<li class="tocline">
<a href="#identifying-unlabeled-nodes" class="tocxref">
<span class="secno">
<del class="diff-old">4.11
</del>
<ins class="diff-chg">4.12
</ins>
</span>
Identifying
Unlabeled
Nodes
</a>
</li>
<li class="tocline">
<a href="#aliasing-keywords" class="tocxref">
<span class="secno">
<del class="diff-old">4.12
</del>
<ins class="diff-chg">4.13
</ins>
</span>
Aliasing
Keywords
</a>
</li>
<li class="tocline">
<a href="#expanded-document-form" class="tocxref">
<span class="secno">
<del class="diff-old">4.13
</del>
<ins class="diff-chg">4.14
</ins>
</span>
Expanded
Document
Form
</a>
</li>
<li class="tocline">
<a href="#compact-document-form" class="tocxref">
<span class="secno">
<del class="diff-old">4.14
</del>
<ins class="diff-chg">4.15
</ins>
</span>
Compact
Document
Form
</a>
</li>
</ul>
</li>
<li class="tocline">
<a href="#json-ld-grammar" class="tocxref">
<span class="secno">
A.
</span>
JSON-LD
<del class="diff-old">Authoring
Guidelines
</del>
<ins class="diff-chg">Grammar
</ins></a><ul class="toc"><li class="tocline"><a href="#grammar-node-definition" class="tocxref"><span class="secno"><ins class="diff-chg">
A.1
</ins></span><ins class="diff-chg">
Node
Definition
</ins>
</a>
</li>
<li class="tocline">
<a href="#grammar-node-reference" class="tocxref">
<span class="secno">
<ins class="diff-chg">A.2
</ins></span><ins class="diff-chg">
Node
Reference
</ins></a></li><li class="tocline"><a href="#grammar-language-map" class="tocxref"><span class="secno"><ins class="diff-chg">
A.3
</ins></span><ins class="diff-chg">
Language
Map
</ins></a></li><li class="tocline"><a href="#grammar-expanded-values" class="tocxref"><span class="secno"><ins class="diff-chg">
A.4
</ins></span><ins class="diff-chg">
Expanded
Values
</ins></a></li><li class="tocline"><a href="#grammar-set-list" class="tocxref"><span class="secno"><ins class="diff-chg">
A.5
</ins></span><ins class="diff-chg">
List
and
Set
Values
</ins></a></li><li class="tocline"><a href="#grammar-context" class="tocxref"><span class="secno"><ins class="diff-chg">
A.6
</ins></span><ins class="diff-chg">
Context
Definition
</ins></a></li></ul></li><li class="tocline"><a href="#relationship-to-other-linked-data-formats-and-data-models" class="tocxref">
<span class="secno">
B.
</span>
Relationship
to
<del class="diff-old">other
RDF
</del>
<ins class="diff-chg">Other
Linked
Data
</ins>
Formats
<ins class="diff-new">and
Data
Models
</ins>
</a>
<ul class="toc">
<li class="tocline">
<a href="#rdf" class="tocxref">
<span class="secno">
B.1
</span>
RDF
</a>
<ul class="toc">
<li class="tocline">
<a href="#turtle" class="tocxref">
<span class="secno">
<del class="diff-old">B.2
</del>
<ins class="diff-chg">B.1.1
</ins>
</span>
Turtle
</a>
<ul class="toc">
<li class="tocline">
<a href="#prefix-definitions" class="tocxref">
<span class="secno">
<del class="diff-old">B.2.1
</del>
<ins class="diff-chg">B.1.1.1
</ins>
</span>
Prefix
definitions
</a>
</li>
<li class="tocline">
<a href="#embedding-1" class="tocxref">
<span class="secno">
<del class="diff-old">B.2.2
</del>
<ins class="diff-chg">B.1.1.2
</ins>
</span>
Embedding
</a>
</li>
<li class="tocline">
<a href="#lists" class="tocxref">
<span class="secno">
<del class="diff-old">B.2.3
</del>
<ins class="diff-chg">B.1.1.3
</ins>
</span>
Lists
</a>
</li>
</ul>
</li>
<li class="tocline">
<a href="#rdfa" class="tocxref">
<span class="secno">
<del class="diff-old">B.3
</del>
<ins class="diff-chg">B.1.2
</ins>
</span>
RDFa
</a>
</li>
<li class="tocline">
<a href="#microformats" class="tocxref">
<span class="secno">
<del class="diff-old">B.4
</del>
<ins class="diff-chg">B.1.3
</ins>
</span>
Microformats
</a>
</li>
<li class="tocline">
<a href="#microdata" class="tocxref">
<span class="secno">
<del class="diff-old">B.5
</del>
<ins class="diff-chg">B.1.4
</ins>
</span>
Microdata
</a>
</li>
</ul>
</li>
<li class="tocline">
<a href="#iana-considerations" class="tocxref">
<span class="secno">
<del class="diff-old">C.
</del>
<ins class="diff-chg">B.2
</ins>
</span>
IANA
Considerations
</a>
</li>
<li class="tocline">
<a href="#acknowledgements" class="tocxref">
<span class="secno">
<del class="diff-old">D.
</del>
<ins class="diff-chg">B.3
</ins>
</span>
Acknowledgements
</a>
</li>
</ul>
</li>
<li class="tocline">
<a href="#references" class="tocxref">
<span class="secno">
<del class="diff-old">E.
</del>
<ins class="diff-chg">C.
</ins>
</span>
References
</a>
<ul class="toc">
<li class="tocline">
<a href="#normative-references" class="tocxref">
<span class="secno">
<del class="diff-old">E.1
</del>
<ins class="diff-chg">C.1
</ins>
</span>
Normative
references
</a>
</li>
<li class="tocline">
<a href="#informative-references" class="tocxref">
<span class="secno">
<del class="diff-old">E.2
</del>
<ins class="diff-chg">C.2
</ins>
</span>
Informative
references
</a>
</li>
</ul>
</li>
</ul>
</section>
<section class="informative" id="introduction">
<h2>
<span class="secno">
1.
</span>
Introduction
</h2>
<p>
<em>
This
section
is
non-normative.
</em>
</p>
<p>
JSON,
as
specified
in
[
<cite>
<a class="bibref" href="#bib-RFC4627">
RFC4627
</a>
</cite>
],
is
a
simple
language
for
representing
data
on
the
Web.
<a class="tref internalDFN" title="linked_data" href="#dfn-linked_data">
Linked
Data
</a>
is
a
technique
for
creating
a
network
of
inter-connected
data
across
different
Web
documents
and
Web
sites.
A
<em>
document
</em>
in
this
data
network
is
typically
identified
using
an
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
(Internationalized
Resource
Identifier).
A
software
program
can
typically
follow
an
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
just
like
you
follow
a
URL
by
putting
it
into
your
browser's
location
bar.
By
following
IRIs,
a
software
program
can
find
more
information
about
the
<em>
document
</em>
and
the
<em>
thing
</em>
s
that
the
document
describes.
These
<em>
things
</em>
may
also
be
identified
using
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
s.
The
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
allows
a
software
program
to
start
at
one
<em>
document
</em>
and
follow
links
to
other
<em>
documents
</em>
or
<em>
things
</em>
in
order
to
learn
more
about
all
of
the
<em>
documents
</em>
and
<em>
things
</em>
described
on
the
Web.
</p>
<p>
JSON-LD
is
designed
as
a
lightweight
syntax
that
can
be
used
to
express
<a class="tref internalDFN" title="linked_data" href="#dfn-linked_data">
Linked
Data
</a>.
It
is
primarily
intended
to
be
a
way
to
use
Linked
Data
in
Javascript
and
other
Web-based
programming
environments.
It
is
also
useful
when
building
inter-operable
Web
services
and
when
storing
Linked
Data
in
JSON-based
document
storage
engines.
It
is
practical
and
designed
to
be
as
simple
as
possible,
utilizing
the
large
number
of
JSON
parsers
and
libraries
available
today.
</p>
<p>
The
syntax
does
not
necessarily
require
applications
to
change
their
JSON,
but
allows
one
to
easily
add
meaning
by
simply
adding
or
referencing
a
context.
The
syntax
is
designed
to
not
disturb
already
deployed
systems
running
on
JSON,
but
provide
a
smooth
upgrade
path
from
JSON
to
JSON-LD.
Finally,
the
format
is
intended
to
be
easy
to
parse,
efficient
to
generate,
and
<del class="diff-old">only
requires
a
</del>
<ins class="diff-chg">can
operate
inside
of
devices
that
contain
</ins>
very
<del class="diff-old">small
memory
footprint
in
order
to
operate.
</del>
<ins class="diff-chg">little
memory.
</ins>
</p>
<section id="how-to-read-this-document">
<h3>
<span class="secno">
1.1
</span>
How
to
Read
this
Document
</h3>
<p>
<em>
This
section
is
non-normative.
</em>
</p>
<p>
This
document
is
a
detailed
specification
for
a
serialization
of
Linked
Data
in
JSON.
The
document
is
primarily
intended
for
the
following
audiences:
</p>
<ul>
<li>
Software
developers
that
want
to
encode
Linked
Data
in
a
<del class="diff-old">way
</del>
<ins class="diff-chg">variety
of
programing
languages
</ins>
that
<del class="diff-old">is
cross-language
compatible
via
</del>
<ins class="diff-chg">can
use
</ins>
JSON.
</li>
<li>
Software
developers
that
want
to
understand
the
design
decisions
and
language
syntax
for
JSON-LD.
</li>
<li>
Software
developers
that
want
to
implement
processors
and
APIs
for
JSON-LD.
</li>
</ul>
<p>
This
specification
does
not
describe
the
programming
interfaces
for
the
JSON-LD
Syntax.
The
specification
that
describes
the
programming
interfaces
for
JSON-LD
documents
is
the
JSON-LD
Application
Programming
Interface
[
<cite>
<a class="bibref" href="#bib-JSON-LD-API">
JSON-LD-API
</a>
</cite>
].
</p>
<p>
To
understand
the
basics
in
this
specification
you
must
first
be
familiar
with
JSON,
which
is
detailed
in
[
<cite>
<a class="bibref" href="#bib-RFC4627">
RFC4627
</a>
</cite>
].
</p>
<del class="diff-old">JSON
[
RFC4627
]
defines
several
terms
which
are
used
throughout
this
document:
JSON
object
An
object
structure
is
represented
as
a
pair
of
curly
brackets
surrounding
zero
or
more
name-value
pairs.
A
name
is
a
string
.
A
single
colon
comes
after
each
name,
separating
the
name
from
the
value.
A
single
comma
separates
a
value
from
a
following
name.
The
names
within
an
object
should
be
unique.
array
In
JSON,
an
array
is
an
ordered
sequence
of
zero
or
more
values.
An
array
is
represented
as
square
brackets
surrounding
zero
or
more
values
that
are
separated
by
commas.
While
JSON-LD
uses
the
same
array
representation
as
JSON,
the
collection
is
unordered
by
default.
While
order
is
preserved
in
regular
JSON
arrays,
it
is
not
in
regular
JSON-LD
arrays
unless
specific
markup
is
provided
(see
Sets
and
Lists
).
string
A
string
is
a
sequence
of
zero
or
more
Unicode
characters,
wrapped
in
double
quotes,
using
backslash
escapes
(if
necessary).
A
character
is
represented
as
a
single
character
string.
number
A
number
is
similar
to
that
used
in
most
programming
languages,
except
that
the
octal
and
hexadecimal
formats
are
not
used
and
that
leading
zeros
are
not
allowed.
true
and
false
Values
that
are
used
to
express
one
of
two
possible
boolean
states.
null
The
null
value
is
used
to
make
the
JSON-LD
processor
&quot;forget&quot;
any
previously
defined
JSON
key
that
is
associated
with
the
null
value.
If
a
previous
definition
doesn't
exist,
the
entire
key-value
is
ignored.
If
a
previous
definition
of
the
key
does
exist,
the
previous
definition
is
undefined.
subject
definition
A
JSON
object
used
to
represent
a
subject
and
one
or
more
properties
of
that
subject.
A
JSON
object
is
a
subject
definition
if
it
does
not
contain
they
keys
@value
,
@list
or
@set
and
it
has
one
or
more
keys
other
than
@id
.
subject
reference
A
JSON
object
used
to
reference
a
subject
having
only
the
@id
key.
</del>
</section>
</section>
<section class="informative" id="design-goals-and-rationale">
<h2>
<span class="secno">
2.
</span>
Design
Goals
and
Rationale
</h2>
<p>
<em>
This
section
is
non-normative.
</em>
</p>
<p>
A
number
of
design
goals
were
established
before
the
creation
of
this
markup
language:
</p>
<dl>
<dt>
Simplicity
</dt>
<dd>
No
extra
processors
or
software
libraries
should
be
necessary
to
use
JSON-LD
in
its
most
basic
form.
The
language
will
provide
developers
with
a
very
easy
learning
curve.
Developers
need
only
know
JSON
and
two
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
keywords
</a>
(
<code>
@context
</code>
and
<code>
@id
</code>
)
to
use
the
basic
functionality
in
JSON-LD.
</dd>
<dt>
Compatibility
</dt>
<dd>
The
JSON-LD
markup
must
be
100%
compatible
with
JSON.
This
ensures
that
all
of
the
standard
JSON
libraries
work
seamlessly
with
JSON-LD
documents.
</dd>
<dt>
Expressiveness
</dt>
<dd>
The
syntax
must
be
able
to
express
directed
graphs,
which
have
been
proven
to
be
able
to
express
almost
every
real
world
data
model.
</dd>
<dt>
Terseness
</dt>
<dd>
The
JSON-LD
syntax
must
be
very
terse
and
human
readable,
requiring
as
little
effort
as
possible
from
the
developer.
</dd>
<dt>
Zero
Edits,
most
of
the
time
</dt>
<dd>
JSON-LD
must
provide
a
<a href="#referencing-contexts-from-json-documents">
mechanism
</a>
that
allows
developers
to
specify
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>
in
a
way
that
is
out-of-band.
This
allows
organizations
that
have
already
deployed
large
JSON-based
infrastructure
to
add
meaning
to
their
JSON
documents
in
a
way
that
is
not
disruptive
to
their
day-to-day
operations
and
is
transparent
to
their
current
customers.
At
times,
mapping
JSON
to
a
graph
representation
can
become
difficult.
In
these
instances,
rather
than
having
JSON-LD
support
an
esoteric
use
case,
we
chose
not
to
support
the
use
case
and
support
a
simplified
syntax
instead.
So,
while
Zero
Edits
is
a
<ins class="diff-new">design
</ins>
goal,
it
is
not
always
possible
without
adding
great
complexity
to
the
language.
</dd>
<dt>
One-pass
Processing
</dt>
<dd>
JSON-LD
supports
one-pass
processing,
which
results
in
a
very
small
memory
footprint
when
processing
documents.
For
example,
to
expand
a
JSON-LD
document
from
a
compacted
form,
only
one
pass
is
required
over
the
data.
</dd>
<dt>
<ins class="diff-new">Linked
Data-centric
</ins></dt><dd><ins class="diff-new">
The
focus
on
Linked
Data
is
placed
at
a
much
higher
priority
than
the
focus
on
the
Semantic
Web.
One
outcome
of
this
ordering
of
priorities
is
an
aggressively
reduced
focus
on
the
Semantic
Web
stack
(RDF
[
</ins><cite><a class="bibref" href="#bib-RDF-CONCEPTS"><ins class="diff-new">
RDF-CONCEPTS
</ins></a></cite><ins class="diff-new">
],
TURTLE
[
</ins><cite><a class="bibref" href="#bib-TURTLE-TR"><ins class="diff-new">
TURTLE-TR
</ins></a></cite><ins class="diff-new">
],
triple
stores,
and
SPARQL
[
</ins><cite><a class="bibref" href="#bib-RDF-SPARQL-QUERY"><ins class="diff-new">
RDF-SPARQL-QUERY
</ins></a></cite><ins class="diff-new">
]).
While
this
may
be
off-putting
to
proponents
of
the
Semantic
Web,
the
audience
for
this
specification
are
Web
developers
that
want
a
gentler
introduction
and
a
simpler
technology
stack
for
using
Linked
Data
in
their
Web
applications.
Semantic
Web
concepts,
such
as
conversion
to
and
from
RDF,
are
fully
supported
by
JSON-LD,
but
the
implementation
of
these
features
are
not
elaborated
upon
in
this
specification.
See
</ins><a href="#relationship-to-other-linked-data-formats-and-data-models" class="sec-ref"><span class="secno"><ins class="diff-new">
B.
</ins></span><span class="sec-title"><ins class="diff-new">
Relationship
to
Other
Linked
Data
Formats
and
Data
Models
</ins></span></a><ins class="diff-new">
for
more
information
about
how
JSON-LD
integrates
into
the
more
traditional
Semantic
Web
stack.
</ins></dd>
</dl>
</section>
<section class="normative" id="basic-concepts">
<h2>
<span class="secno">
3.
</span>
Basic
Concepts
</h2>
<em>
This
section
is
normative.
</em>
<p>
JSON-LD
is
designed
to
ensure
that
<a class="tref internalDFN" title="linked_data" href="#dfn-linked_data">
Linked
Data
</a>
concepts
can
be
marked
up
in
a
way
that
is
simple
to
understand
and
create
by
Web
authors.
In
many
cases,
regular
JSON
markup
can
become
Linked
Data
with
the
simple
addition
of
a
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>.
As
more
JSON-LD
features
are
used,
more
semantics
are
added
to
the
JSON
markup.
</p>
<section id="benefits-of-json-ld">
<h3>
<span class="secno">
3.1
</span>
<del class="diff-old">Linking
Data
</del>
<ins class="diff-chg">Benefits
of
JSON-LD
</ins>
</h3>
<p>
<del class="diff-old">The
following
definition
</del>
<ins class="diff-chg">JSON
provides
a
number
of
benefits
to
software
developers
that
need
to
serialize
data:
</ins></p><ol><li><ins class="diff-chg">
It
is
easy
</ins>
for
<del class="diff-old">Linked
Data
</del>
<ins class="diff-chg">humans
to
read
and
write.
</ins></li><li><ins class="diff-chg">
It
is
easy
for
machines
to
parse
and
generate.
</ins></li><li><ins class="diff-chg">
It
has
a
syntax
that
is
familiar
across
a
large
number
of
programming
languages.
</ins></li><li><ins class="diff-chg">
It
</ins>
is
<ins class="diff-new">capable
of
representing
many
different
types
of
data
using
two
universal
data
structures;
a
collection
of
key-value
pairs
and
lists.
</ins></li></ol><p><ins class="diff-new">
JSON
has
become
a
very
popular
data-interchange
format
on
</ins>
the
<del class="diff-old">one
</del>
<ins class="diff-chg">Web,
particularly
for
</ins><a href="http://en.wikipedia.org/wiki/REST"><ins class="diff-chg">
REST
</ins></a><ins class="diff-chg">
-based
Web
Services.
Unfortunately,
it
has
a
number
of
short-comings
</ins>
that
<del class="diff-old">will
be
</del>
<ins class="diff-chg">other
Web-native
data
formats
do
not
have:
</ins></p><ol><li><ins class="diff-chg">
There
is
no
standardized,
universal
identifier
mechanism
for
</ins><a class="tref internalDFN" title="json_object" href="#dfn-json_object"><ins class="diff-chg">
JSON
object
</ins></a><ins class="diff-chg">
s.
</ins></li><li><ins class="diff-chg">
The
meaning
of
the
keys
</ins>
used
<ins class="diff-new">in
a
</ins><a class="tref internalDFN" title="json_object" href="#dfn-json_object"><ins class="diff-new">
JSON
object
</ins></a><ins class="diff-new">
s
are
ambiguous
and
often
conflict
with
other
data
published
on
the
Web.
</ins></li><li><ins class="diff-new">
There
is
no
standardized
way
</ins>
for
<del class="diff-old">this
specification.
</del>
<ins class="diff-chg">a
value
in
a
</ins><a class="tref internalDFN" title="json_object" href="#dfn-json_object"><ins class="diff-chg">
JSON
object
</ins></a><ins class="diff-chg">
to
refer
to
a
</ins><a class="tref internalDFN" title="json_object" href="#dfn-json_object"><ins class="diff-chg">
JSON
object
</ins></a><ins class="diff-chg">
on
a
different
site
on
the
Web.
</ins></li><li><ins class="diff-chg">
A
developer
cannot
express
the
language
associated
with
a
</ins><a class="tref internalDFN" title="string" href="#dfn-string"><ins class="diff-chg">
string
</ins></a><ins class="diff-chg">
value
in
a
standardized
manner.
</ins></li><li><ins class="diff-chg">
There
is
no
standard
mechanism
to
associate
datatypes
with
values
such
as
dates,
times,
weights,
and
distances.
</ins></li><li><ins class="diff-chg">
There
is
no
facility
to
express
a
Web
of
information
(directed
graph),
such
as
a
social
network,
in
a
standardized
manner.
</ins></li></ol><p><ins class="diff-chg">
JSON-LD
is
a
web-native
standard,
is
100%
compatible
with
JSON,
provides
all
of
the
facilities
that
JSON
provides,
and
extends
the
language
to
provide
the
following
core
advantages:
</ins>
</p>
<ol>
<li>
<ins class="diff-new">A
universal
identifier
mechanism
for
</ins><a class="tref internalDFN" title="json_object" href="#dfn-json_object"><ins class="diff-new">
JSON
object
</ins></a><ins class="diff-new">
s
via
the
use
of
</ins><a class="tref internalDFN" title="iri" href="#dfn-iri"><abbr title="Internationalized Resource Identifier"><ins class="diff-new">
IRI
</ins></abbr></a><ins class="diff-new">
s.
</ins></li><li><ins class="diff-new">
A
way
to
dis-ambiguate
the
keys
used
between
multiple
JSON
documents
by
mapping
them
to
</ins><a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
<ins class="diff-new">IRI
</ins></abbr></a><ins class="diff-new">
s
via
a
</ins><a class="tref internalDFN" title="context" href="#dfn-context"><ins class="diff-new">
context
</ins></a>.</li><li><ins class="diff-new">
A
mechanism
in
which
a
value
in
a
</ins><a class="tref internalDFN" title="json_object" href="#dfn-json_object"><ins class="diff-new">
JSON
object
</ins></a><ins class="diff-new">
may
refer
to
a
</ins><a class="tref internalDFN" title="json_object" href="#dfn-json_object"><ins class="diff-new">
JSON
object
</ins></a><ins class="diff-new">
on
a
different
site
on
the
Web.
</ins></li><li><ins class="diff-new">
The
ability
to
express
the
language
associated
with
a
</ins><a class="tref internalDFN" title="string" href="#dfn-string"><ins class="diff-new">
string
</ins></a><ins class="diff-new">
value.
</ins></li><li><ins class="diff-new">
A
way
to
associate
datatypes
with
values
such
as
dates,
times,
weights,
and
distances.
</ins></li><li><ins class="diff-new">
A
facility
to
express
one
or
more
directed
graphs,
such
as
a
social
network,
in
a
single
document.
</ins></li></ol><p><ins class="diff-new">
Developers
that
require
any
of
the
facilities
listed
above
will
find
JSON-LD
of
interest.
</ins></p></section><section id="json-ld-data-model"><h3><span class="secno"><ins class="diff-new">
3.2
</ins></span><ins class="diff-new">
JSON-LD
Data
Model
</ins></h3><p>
<dfn title="linked_data" id="dfn-linked_data">
Linked
Data
</dfn>
is
a
<del class="diff-old">set
</del>
<ins class="diff-chg">way
</ins>
of
<del class="diff-old">documents,
each
containing
a
representation
</del>
<ins class="diff-chg">publishing
data
on
the
Web.
In
general,
Linked
Data
has
four
properties;
1)
It
uses
</ins><a class="tref internalDFN" title="iri" href="#dfn-iri"><abbr title="Internationalized Resource Identifier"><ins class="diff-chg">
IRI
</ins></abbr></a><ins class="diff-chg">
s
to
name
</ins><em><ins class="diff-chg">
things
</ins></em>,<ins class="diff-chg">
2)
It
uses
HTTP
</ins><a class="tref internalDFN" title="iri" href="#dfn-iri"><abbr title="Internationalized Resource Identifier"><ins class="diff-chg">
IRI
</ins></abbr></a><ins class="diff-chg">
s
for
those
names,
3)
The
name
links,
when
followed,
provide
more
information
about
the
name,
and
4)
The
data
expresses
links
to
data
on
other
Web
sites.
These
properties
allow
data
published
on
the
Web
to
work
much
like
Web
pages
do
today.
One
can
start
at
one
piece
</ins>
of
<ins class="diff-new">Linked
Data,
and
follow
the
links
to
other
pieces
of
data
that
are
hosted
on
different
sites
across
the
Web.
</ins></p><p><ins class="diff-new">
JSON-LD
is
</ins>
a
<ins class="diff-new">way
of
expressing
</ins><a class="tref internalDFN" title="linked_data" href="#dfn-linked_data"><ins class="diff-new">
Linked
Data
</ins></a><ins class="diff-new">
on
the
Web.
The
JSON-LD
data
model
encapsulates
the
following
concepts:
</ins></p><ol><li><ins class="diff-new">
The
JSON-LD
data
model
is
used
to
represent
</ins>
<a class="tref internalDFN" title="linked_data_graph" href="#dfn-linked_data_graph">
linked
data
graph
<del class="diff-old">.
</del>
</a>
<ins class="diff-chg">s.
</ins>
</li>
<li>
A
<dfn title="linked_data_graph" id="dfn-linked_data_graph">
linked
data
graph
</dfn>
is
an
unordered
labeled
directed
graph,
where
<del class="diff-old">nodes
are
</del>
<ins class="diff-chg">each
</ins><dfn title="node" id="dfn-node"><ins class="diff-chg">
node
</ins></dfn><ins class="diff-chg">
is
a
</ins>
<a class="tref internalDFN" title="subject" href="#dfn-subject">
subject
</a>
<del class="diff-old">s
</del>
or
<a class="tref internalDFN" title="object" href="#dfn-object">
object
<del class="diff-old">s,
</del>
</a>,
and
edges
are
labeled
using
<a class="tref internalDFN" title="property" href="#dfn-property">
properties
</a>.
</li>
<li>
A
<dfn title="subject" id="dfn-subject">
subject
</dfn>
is
any
node
in
a
<a class="tref internalDFN" title="linked_data_graph" href="#dfn-linked_data_graph">
linked
data
graph
</a>
with
at
least
one
outgoing
edge.
</li>
<li>
A
<a class="tref internalDFN" title="subject" href="#dfn-subject">
subject
</a>
<em class="rfc2119" title="should">
should
</em>
be
labeled
with
an
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
(an
Internationalized
Resource
Identifier
as
described
in
[
<cite>
<a class="bibref" href="#bib-RFC3987">
RFC3987
</a>
</cite>
]).
</li>
<li>
An
<dfn title="object" id="dfn-object">
object
</dfn>
is
a
node
in
a
<a class="tref internalDFN" title="linked_data_graph" href="#dfn-linked_data_graph">
linked
data
graph
</a>
with
at
least
one
incoming
edge.
</li>
<li>
An
<a class="tref internalDFN" title="object" href="#dfn-object">
object
</a>
<em class="rfc2119" title="may">
may
</em>
be
labeled
with
an
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
or
a
label
that
is
not
an
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
such
as
plain
text,
internationalized
text,
or
a
strictly-typed
data
value.
</li>
<li>
A
<a class="tref internalDFN" title="node" href="#dfn-node">
node
</a>
<em class="rfc2119" title="may">
may
</em>
be
a
<a class="tref internalDFN" title="subject" href="#dfn-subject">
subject
</a>
and
an
<a class="tref internalDFN" title="object" href="#dfn-object">
object
</a>
at
the
same
time.
</li>
<li>
A
<dfn title="property" id="dfn-property">
property
</dfn>
is
the
label
on
an
edge
in
a
<a class="tref internalDFN" title="linked_data_graph" href="#dfn-linked_data_graph">
linked
data
graph
</a>.
</li>
<li>
A
<a class="tref internalDFN" title="property" href="#dfn-property">
property
</a>
<em class="rfc2119" title="should">
should
</em>
be
an
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>.
</li>
<li>
An
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
that
is
a
label
in
a
<a class="tref internalDFN" title="linked_data_graph" href="#dfn-linked_data_graph">
linked
data
graph
</a>
<em class="rfc2119" title="should">
should
</em>
be
dereferencable
to
a
<a class="tref internalDFN" title="linked_data" href="#dfn-linked_data">
Linked
Data
</a>
document
describing
the
labeled
<a class="tref internalDFN" title="subject" href="#dfn-subject">
subject
</a>,
<a class="tref internalDFN" title="property" href="#dfn-property">
property
</a>
or
<a class="tref internalDFN" title="object" href="#dfn-object">
object
</a>.
</li>
</ol>
<del class="diff-old">Issue
1
An
illustration
of
a
linked
data
graph
would
probably
help
here.
Issue
2
EricP
suggests
that
the
definitions
of
subject
and
object,
while
being
practical,
are
at
odds
with
[
RDF-CONCEPTS
]
use
in
their
roles
within
a
triple.
</del>
<div class="note">
<div class="note-title">
<span>
Note
</span>
</div>
<del class="diff-old">JSON-LD
allows
properties
to
be
BNodes,
while
RDF
</del>
<div class="">
<p>
<ins class="diff-chg">A
</ins><a class="tref internalDFN" title="linked_data" href="#dfn-linked_data"><ins class="diff-chg">
Linked
Data
</ins></a><ins class="diff-chg">
document
</ins>
does
<del class="diff-old">not.
When
used
as
just
JSON-LD,
this
is
</del>
not
<del class="diff-old">unreasonable;
it
only
becomes
an
issue
(and
could
raise
an
exception)
when
transformed
</del>
<ins class="diff-chg">necessarily
need
</ins>
to
<del class="diff-old">RDF.
Note
that
the
definition
for
</del>
<ins class="diff-chg">be
expressed
in
JSON-LD.
The
notion
of
</ins>
<a class="tref internalDFN" title="linked_data" href="#dfn-linked_data">
Linked
Data
</a>
<del class="diff-old">above
</del>
is
<del class="diff-old">silent
on
the
topic
</del>
<ins class="diff-chg">a
concept
independent
</ins>
of
<del class="diff-old">unlabeled
nodes
.
Nevertheless,
this
specification
allows
for
the
expression
</del>
<ins class="diff-chg">any
given
serialization
format.
</ins></p></div></div><img style="padding: 5px; border-style: solid; border-width: 1px; display: block; margin-left: auto; margin-right: auto;" src="linked-data-graph.png" title="An example of a linked data graph" longdesc="An example of a linked data graph showing two main nodes labeled with URLs for Alice and Bob. The Alice node contains two other connected nodes showing Alice's age (32) and name (Alice)." /><p style="text-align: center;"><ins class="diff-chg">
Figure
1:
An
example
</ins>
of
<del class="diff-old">unlabeled
nodes
,
as
most
graph-based
</del>
<ins class="diff-chg">a
linked
</ins>
data
<del class="diff-old">sets
on
the
Web
contain
</del>
<ins class="diff-chg">graph.
</ins></p><p><ins class="diff-chg">
There
are
</ins>
a
number
of
<del class="diff-old">associated
nodes
</del>
<ins class="diff-chg">best
practices
</ins>
that
<del class="diff-old">are
not
named
and
thus
are
not
directly
de-referenceable.
</del>
<ins class="diff-chg">can
ensure
that
developers
will
generate
good
Linked
Data
for
the
Web.
</ins>
JSON-LD
<del class="diff-old">defines
</del>
<ins class="diff-chg">formalizes
those
techniques
by
providing
</ins>
a
mechanism
to
map
JSON
<del class="diff-old">terms,
</del>
<ins class="diff-chg">data,
</ins>
i.e.,
keys
and
values,
to
<del class="diff-old">IRIs.
</del>
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
<ins class="diff-chg">IRI
</ins></abbr></a><ins class="diff-chg">
s.
</ins>
This
does
not
mean
that
JSON-LD
requires
every
key
or
value
to
be
an
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>,
but
rather
ensures
that
keys
and
values
can
be
mapped
to
IRIs
if
the
developer
desires
to
transform
their
data
into
<a class="tref internalDFN" title="linked_data" href="#dfn-linked_data">
Linked
Data
</a>.
<del class="diff-old">There
are
a
few
techniques
that
can
ensure
that
developers
will
generate
good
Linked
Data
for
the
Web.
JSON-LD
formalizes
those
techniques.
</del>
</p>
</section>
<section id="general-terminology">
<h3>
<span class="secno">
<ins class="diff-new">3.3
</ins></span><ins class="diff-new">
General
Terminology
</ins></h3>
<p>
<del class="diff-old">We
will
</del>
<ins class="diff-chg">The
following
is
an
explanation
of
the
general
terminology
used
in
this
document.
Many
of
the
terms
should
</ins>
be
<del class="diff-old">using
</del>
<ins class="diff-chg">familiar
to
developers
that
have
used
JSON:
</ins></p><dl><dt><dfn title="json_object" id="dfn-json_object"><ins class="diff-chg">
JSON
object
</ins></dfn></dt><dd><ins class="diff-chg">
An
object
structure
is
represented
as
a
pair
of
curly
brackets
surrounding
zero
or
more
key-value
pairs.
A
key
is
a
</ins><a class="tref internalDFN" title="string" href="#dfn-string"><ins class="diff-chg">
string
</ins></a>.<ins class="diff-chg">
A
single
colon
comes
after
each
key,
separating
the
key
from
</ins>
the
<ins class="diff-new">value.
A
single
comma
separates
a
value
from
a
</ins>
following
<ins class="diff-new">key.
The
keys
within
an
object
</ins><em class="rfc2119" title="should"><ins class="diff-new">
should
</ins></em><ins class="diff-new">
be
unique.
</ins></dd><dt><dfn title="array" id="dfn-array"><ins class="diff-new">
array
</ins></dfn></dt><dd><ins class="diff-new">
In
JSON,
an
array
is
an
</ins><em><ins class="diff-new">
ordered
</ins></em><ins class="diff-new">
sequence
of
zero
or
more
values.
An
array
is
represented
as
square
brackets
surrounding
zero
or
more
values
that
are
separated
by
commas.
While
JSON-LD
uses
the
same
array
representation
as
JSON,
the
collection
is
</ins><em><ins class="diff-new">
unordered
</ins></em><ins class="diff-new">
by
default.
While
order
is
preserved
in
regular
</ins>
JSON
<ins class="diff-new">arrays,
it
is
not
in
regular
JSON-LD
arrays
unless
specific
</ins>
markup
<ins class="diff-new">is
provided
(see
</ins><a href="#sets-and-lists" class="sec-ref"><span class="secno"><ins class="diff-new">
4.9
</ins></span><span class="sec-title"><ins class="diff-new">
Sets
and
Lists
</ins></span></a><ins class="diff-new">
).
</ins></dd><dt><dfn title="string" id="dfn-string"><ins class="diff-new">
string
</ins></dfn></dt><dd><ins class="diff-new">
A
string
is
a
sequence
of
zero
or
more
Unicode
characters,
wrapped
in
double
quotes,
using
backslash
escapes
(if
necessary).
A
character
is
represented
</ins>
as
<ins class="diff-new">a
single
character
string.
</ins></dd><dt><dfn title="number" id="dfn-number"><ins class="diff-new">
number
</ins></dfn></dt><dd><ins class="diff-new">
A
number
is
similar
to
that
used
in
most
programming
languages,
except
that
</ins>
the
<del class="diff-old">example
for
</del>
<ins class="diff-chg">octal
and
hexadecimal
formats
are
not
used
and
that
leading
zeros
are
not
allowed.
</ins></dd><dt><dfn title="true" id="dfn-true"><ins class="diff-chg">
true
</ins></dfn><ins class="diff-chg">
and
</ins><dfn title="false" id="dfn-false"><ins class="diff-chg">
false
</ins></dfn></dt><dd><ins class="diff-chg">
Values
that
are
used
to
express
one
of
two
possible
boolean
states.
</ins></dd><dt><dfn title="null" id="dfn-null"><ins class="diff-chg">
null
</ins></dfn></dt><dd><ins class="diff-chg">
The
null
value
is
used
to
make
a
JSON-LD
processor
&quot;forget&quot;
any
previously
defined
JSON
key
that
is
associated
with
</ins>
the
<del class="diff-old">rest
</del>
<ins class="diff-chg">null
value.
If
a
previous
definition
doesn't
exist,
the
entire
key-value
is
ignored.
If
a
previous
definition
</ins>
of
<del class="diff-old">this
section:
{
  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;,
  &quot;depiction&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;
}
</del>
<ins class="diff-chg">the
key
does
exist,
the
previous
definition
is
undefined.
</ins></dd><dt>
<dfn title="node_definition" id="dfn-node_definition">
<ins class="diff-chg">node
definition
</ins></dfn></dt><dd><ins class="diff-chg">
A
</ins><a class="tref internalDFN" title="json_object" href="#dfn-json_object"><ins class="diff-chg">
JSON
object
</ins></a><ins class="diff-chg">
used
to
represent
a
</ins><a class="tref internalDFN" title="node" href="#dfn-node"><ins class="diff-chg">
node
</ins></a><ins class="diff-chg">
and
one
or
more
properties
of
that
node.
A
</ins><a class="tref internalDFN" title="json_object" href="#dfn-json_object"><ins class="diff-chg">
JSON
object
</ins></a><ins class="diff-chg">
is
a
node
definition
if
it
does
not
contain
the
keys
</ins><code><ins class="diff-chg">
@value
</ins></code>,<code><ins class="diff-chg">
@list
</ins></code><ins class="diff-chg">
or
</ins><code><ins class="diff-chg">
@set
</ins></code><ins class="diff-chg">
and
it
has
one
or
more
keys
other
than
</ins><code><ins class="diff-chg">
@id
</ins></code>.<ins class="diff-chg">
A
node
definition
</ins><em class="rfc2119" title="may"><ins class="diff-chg">
may
</ins></em><ins class="diff-chg">
be
spread
among
different
parts
of
a
document
or
even
between
different
documents.
</ins></dd><dt><dfn title="node_reference" id="dfn-node_reference"><ins class="diff-chg">
node
reference
</ins></dfn></dt><dd><ins class="diff-chg">
A
</ins><a class="tref internalDFN" title="json_object" href="#dfn-json_object"><ins class="diff-chg">
JSON
object
</ins></a><ins class="diff-chg">
used
to
refer
to
a
node
that
contains
a
single
key-value
pair
where
the
key
is
</ins><code><ins class="diff-chg">
@id
</ins></code>.</dd></dl><p></p></section><section id="syntax-tokens-and-keywords"><h3>
<span class="secno">
<del class="diff-old">3.1.1
</del>
<ins class="diff-chg">3.4
</ins>
</span>
Syntax
Tokens
and
Keywords
</h3>
<p>
JSON-LD
specifies
a
number
of
syntax
tokens
and
<dfn title="keyword" id="dfn-keyword">
keywords
</dfn>
that
are
a
core
part
of
the
language:
</p>
<dl>
<dt>
<code>
@context
</code>
</dt>
<dd>
Used
to
define
the
short-hand
names
that
are
used
throughout
a
JSON-LD
document.
These
short-hand
names
are
called
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
s
and
help
developers
to
express
specific
identifiers
in
a
compact
manner.
The
<code>
@context
</code>
keyword
is
described
in
detail
in
the
section
titled
<a href="#the-context" class="sec-ref">
<span class="secno">
<ins class="diff-chg">3.5
</ins></span><span class="sec-title">
The
Context
</span>
</a>.
</dd>
<dt>
<code>
@graph
</code>
</dt>
<dd>
Used
to
explicitly
label
a
<a class="tref internalDFN" title="linked_data_graph" href="#dfn-linked_data_graph">
linked
data
graph
</a>.
This
keyword
is
described
in
<del class="diff-old">the
section
titled
</del>
<a href="#named-graphs" class="sec-ref">
<span class="secno">
<ins class="diff-chg">4.11
</ins></span><span class="sec-title">
Named
Graphs
</span>
</a>.
</dd>
<dt>
<code>
@id
</code>
</dt>
<dd>
Used
to
uniquely
identify
<em>
things
</em>
that
are
being
described
in
the
document.
This
keyword
is
described
in
<del class="diff-old">the
section
titled
Identifying
the
Subject
</del>
<a href="#node-identifiers" class="sec-ref">
<span class="secno">
<ins class="diff-chg">3.8
</ins></span><span class="sec-title"><ins class="diff-chg">
Node
Identifiers
</ins></span>
</a>.
</dd>
<dt>
<code>
@value
</code>
</dt>
<dd>
Used
to
specify
the
data
that
is
associated
with
a
particular
<a class="tref internalDFN" title="property" href="#dfn-property">
property
</a>
in
the
graph.
This
keyword
is
described
in
<del class="diff-old">the
sections
titled
</del>
<a href="#string-internationalization" class="sec-ref">
<span class="secno">
<ins class="diff-chg">3.10
</ins></span><span class="sec-title">
String
Internationalization
</span>
</a>
and
<a href="#typed-values" class="sec-ref">
<span class="secno">
<ins class="diff-chg">4.2
</ins></span><span class="sec-title">
Typed
Values
</span>
</a>.
</dd>
<dt>
<code>
@language
</code>
</dt>
<dd>
Used
to
specify
the
native
language
for
a
particular
value
or
the
default
language
of
a
JSON-LD
document.
This
keyword
is
described
in
the
section
titled
<a href="#string-internationalization" class="sec-ref">
<span class="secno">
<ins class="diff-chg">3.10
</ins></span><span class="sec-title">
String
Internationalization
</span>
</a>.
</dd>
<dt>
<code>
@type
</code>
</dt>
<dd>
Used
to
set
the
data
type
of
a
<del class="diff-old">subject
</del>
<a class="tref internalDFN" title="node" href="#dfn-node">
<ins class="diff-chg">node
</ins>
</a>
or
<a class="tref internalDFN" title="typed_value" href="#dfn-typed_value">
typed
value
</a>.
This
keyword
is
described
in
the
section
titled
<a href="#typed-values" class="sec-ref">
<span class="secno">
<ins class="diff-chg">4.2
</ins></span><span class="sec-title">
Typed
Values
</span>
</a>.
</dd>
<dt>
<code>
@container
</code>
</dt>
<dd>
Used
to
set
the
container
of
a
particular
value.
This
keyword
is
described
in
the
section
titled
<a href="#sets-and-lists" class="sec-ref">
<span class="secno">
<ins class="diff-chg">4.9
</ins></span><span class="sec-title">
Sets
and
Lists
</span>
</a>.
</dd>
<dt>
<code>
@list
</code>
</dt>
<dd>
Used
to
express
an
ordered
set
of
data.
This
keyword
is
described
in
the
section
titled
<a href="#sets-and-lists" class="sec-ref">
<span class="secno">
<ins class="diff-chg">4.9
</ins></span><span class="sec-title">
Sets
and
Lists
</span>
</a>.
</dd>
<dt>
<code>
@set
</code>
</dt>
<dd>
Used
to
express
an
unordered
set
of
data.
This
keyword
is
described
in
the
section
titled
<a href="#sets-and-lists" class="sec-ref">
<span class="secno">
<ins class="diff-chg">4.9
</ins></span><span class="sec-title">
Sets
and
Lists
</span>
</a>.
</dd>
<dt>
<code>
<ins class="diff-new">@vocab
</ins></code></dt><dd><ins class="diff-new">
Used
to
set
the
base
</ins><a class="tref internalDFN" title="iri" href="#dfn-iri"><abbr title="Internationalized Resource Identifier"><ins class="diff-new">
IRI
</ins></abbr></a><ins class="diff-new">
for
all
property
IRIs
affected
by
the
</ins><a class="tref internalDFN" title="active_context" href="#dfn-active_context"><ins class="diff-new">
active
context
</ins></a>.<ins class="diff-new">
This
keyword
is
described
in
section
</ins><a href="#iris" class="sec-ref"><span class="secno"><ins class="diff-new">
3.7
</ins></span><span class="sec-title"><ins class="diff-new">
IRIs
</ins></span>
</a>.
</dd>
<dt>
<code>:
</code>
</dt>
<dd>
The
separator
for
JSON
keys
and
values
that
use
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
compact
IRIs
</a>.
</dd>
</dl>
<p>
For
the
avoidance
of
doubt,
all
keys,
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
keywords
</a>,
and
values
in
JSON-LD
are
case-sensitive.
</p>
</section>
<section id="the-context">
<h3>
<span class="secno">
<del class="diff-old">3.1.2
</del>
<ins class="diff-chg">3.5
</ins>
</span>
The
Context
</h3>
<p>
In
JSON-LD,
a
<dfn title="context" id="dfn-context">
context
</dfn>
is
used
to
map
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
s,
i.e.,
properties
with
associated
values
in
an
JSON
document,
to
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
s.
A
<dfn title="term" id="dfn-term">
term
</dfn>
is
a
short
word
that
expands
to
an
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>.
<a class="tref internalDFN" title="term" href="#dfn-term">
Term
</a>
s
<em class="rfc2119" title="may">
may
</em>
be
defined
as
any
valid
JSON
<a class="tref internalDFN" title="string" href="#dfn-string">
string
</a>
other
than
a
JSON-LD
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
keyword
</a>.
To
avoid
forward-compatibility
issues,
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
s
starting
with
an
<code>
@
</code>
character
<em class="rfc2119" title="should not">
should
not
</em>
be
used
as
they
might
be
used
as
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
keywords
</a>
in
future
versions
of
JSON-LD.
Furthermore,
the
use
of
empty
terms
(
<code>
&quot;&quot;
</code>
)
is
discouraged
as
not
all
programming
languages
are
able
to
handle
empty
property
names.
</p>
<p>
The
Web
uses
<a class="tref internalDFN" title="iri" href="#dfn-iri">
IRIs
</a>
for
unambiguous
identification.
The
idea
is
that
these
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
s
mean
something
that
may
be
of
use
to
other
developers
and
that
it
is
useful
to
give
them
an
unambiguous
identifier.
That
is,
it
is
useful
for
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
s
to
expand
to
IRIs
so
that
developers
don't
accidentally
step
on
each
other's
<dfn title="vocabulary" id="dfn-vocabulary">
vocabulary
</dfn>
terms
and
other
resources.
Furthermore,
developers,
and
machines,
are
able
to
use
this
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
(by
plugging
it
directly
into
a
web
browser,
for
instance)
to
go
to
the
term
and
get
a
definition
of
what
the
term
means.
This
mechanism
is
analogous
to
the
way
we
can
use
<a href="http://wordnet.princeton.edu/">
WordNet
</a>
today
to
see
the
definition
of
words
in
the
English
language.
Developers
and
machines
need
the
same
sort
of
definition
of
terms.
<a class="tref internalDFN" title="iri" href="#dfn-iri">
IRIs
</a>
provide
a
way
to
ensure
that
these
terms
are
unambiguous.
For
example,
the
term
<code>
name
</code>
may
map
directly
to
the
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
<code>
http://xmlns.com/foaf/0.1/name
</code>.
This
allows
JSON-LD
documents
to
be
constructed
using
the
common
JSON
practice
of
simple
<del class="diff-old">name/value
</del>
<ins class="diff-chg">key-value
</ins>
pairs
while
ensuring
that
the
data
is
useful
outside
of
the
page,
API
or
database
in
which
it
resides.
The
value
of
a
term
mapping
<em class="rfc2119" title="must">
must
</em>
be
either;
1)
a
simple
string
with
the
lexical
form
of
an
<a class="tref internalDFN" title="absolute_iri" href="#dfn-absolute_iri">
absolute
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
or
2)
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
compact
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>,
or
3)
an
<a class="tref internalDFN" title="json_object" href="#dfn-json_object">
JSON
object
</a>
containing
an
<code>
@id
</code>,
<code>
@type
</code>,
<code>
@language
</code>,
or
<code>
@container
</code>
keyword
(all
other
keywords
are
ignored
by
a
JSON-LD
processor).
</p>
<p>
These
Linked
Data
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
s
are
typically
collected
in
a
context
document
that
would
look
something
like
this:
</p>
<del class="diff-old">{
</del>
<div class="example"><div class="example-title"><span>Example 1</span>: Context definition</div><pre class="example">{
  &quot;@context&quot;:
  {
    &quot;name&quot;: &quot;http://xmlns.com/foaf/0.1/name&quot;,
    &quot;depiction&quot;:
    {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/depiction&quot;,
      &quot;@type&quot;: &quot;@id&quot;
    },
    &quot;homepage&quot;:
    {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/homepage&quot;,
      &quot;@type&quot;: &quot;@id&quot;
    },
  }
}
</pre>
</div>
<p>
<del class="diff-old">Assuming
</del>
<ins class="diff-chg">Let's
assume
</ins>
that
<del class="diff-old">this
context
document
can
be
retrieved
at
http://json-ld.org/contexts/person.jsonld
,
it
can
be
referenced
from
</del>
a
<del class="diff-old">JSON-LD
document
by
adding
</del>
<ins class="diff-chg">developer
starts
with
the
following
JSON
document:
</ins></p><div class="example"><div class="example-title"><span>Example 2</span>: Sample JSON object</div><pre class="example">{<ins class="diff-chg">
  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;,
  &quot;depiction&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;
}
</ins></pre></div><p><ins class="diff-chg">
The
developer
can
add
</ins>
a
single
<del class="diff-old">line.
The
</del>
<ins class="diff-chg">line
to
the
</ins>
JSON
<del class="diff-old">markup
shown
in
</del>
<ins class="diff-chg">document
above
to
reference
</ins>
the
<del class="diff-old">previous
section
could
be
changed
as
follows:
</del>
<ins class="diff-chg">context
and
transform
it
into
a
JSON-LD
document:
</ins>
</p>
<del class="diff-old">{
</del>
<div class="example"><div class="example-title"><span>Example 3</span>: Adding context reference to JSON document</div><pre class="example">{
  <span class="diff">&quot;@context&quot;: &quot;http://json-ld.org/contexts/person.jsonld&quot;,</span>
  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;,
  &quot;depiction&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;
}
</pre>
</div>
<p>
The
additions
above
transform
the
previous
JSON
document
into
a
JSON
document
with
added
semantics
because
the
<code>
@context
</code>
specifies
how
the
<strong>
name
</strong>,
<strong>
homepage
</strong>,
and
<strong>
depiction
</strong>
terms
map
to
<a class="tref internalDFN" title="iri" href="#dfn-iri">
IRIs
</a>.
Mapping
those
keys
to
IRIs
gives
the
data
global
context.
If
two
developers
use
the
same
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
to
describe
a
property,
they
are
more
than
likely
expressing
the
same
concept.
This
allows
both
developers
to
re-use
each
others'
data
without
having
to
agree
to
how
their
data
will
interoperate
on
a
site-by-site
basis.
Contexts
may
also
contain
type
information
for
certain
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
s
as
well
as
other
processing
instructions
for
the
JSON-LD
processor.
</p>
<div class="note">
<div class="note-title">
<span>
<ins class="diff-new">Note
</ins></span></div><p class=""><ins class="diff-new">
External
JSON-LD
context
documents
</ins><em class="rfc2119" title="may"><ins class="diff-new">
may
</ins></em><ins class="diff-new">
contain
extra
information
located
outside
of
the
</ins><code><ins class="diff-new">
@context
</ins></code><ins class="diff-new">
key,
such
as
documentation
about
the
</ins><a class="tref internalDFN" title="term" href="#dfn-term"><ins class="diff-new">
terms
</ins></a><ins class="diff-new">
declared
in
the
document.
When
importing
a
</ins><code><ins class="diff-new">
@context
</ins></code><ins class="diff-new">
value
from
an
external
JSON-LD
context
document,
any
extra
information
contained
outside
of
the
</ins><code><ins class="diff-new">
@context
</ins></code><ins class="diff-new">
value
</ins><em class="rfc2119" title="must"><ins class="diff-new">
must
</ins></em><ins class="diff-new">
be
discarded.
</ins></p></div>
<p>
Contexts
<em class="rfc2119" title="may">
may
</em>
be
specified
in-line.
This
ensures
that
JSON-LD
documents
can
be
processed
when
a
JSON-LD
processor
does
not
have
access
to
the
Web.
</p>
<del class="diff-old">{
</del>
<div class="example"><div class="example-title"><span>Example 4</span>: In-line context definition</div><pre class="example">{
  <span class="diff">&quot;@context&quot;:
  {
    &quot;name&quot;: &quot;http://xmlns.com/foaf/0.1/name&quot;,
    &quot;depiction&quot;:
    {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/depiction&quot;,
      &quot;@type&quot;: &quot;@id&quot;
    },
    &quot;homepage&quot;:
    {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/homepage&quot;,
      &quot;@type&quot;: &quot;@id&quot;
    },
  },</span>
  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;,
  &quot;depiction&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;
}
</pre>
</div>
<p>
Contexts
<em class="rfc2119" title="may">
may
</em>
be
used
at
any
time
a
<del class="diff-old">subject
</del>
<a class="tref internalDFN" title="node_definition" href="#dfn-node_definition">
<ins class="diff-chg">node
</ins>
definition
</a>
is
defined.
A
<del class="diff-old">subject
</del>
<a class="tref internalDFN" title="node_definition" href="#dfn-node_definition">
<ins class="diff-chg">node
</ins>
definition
</a>
<em class="rfc2119" title="may">
may
</em>
specify
multiple
contexts,
using
an
<a class="tref internalDFN" title="array" href="#dfn-array">
array
</a>,
which
is
processed
in
order.
This
is
useful
when
an
author
would
like
to
use
an
existing
context
and
add
application-specific
terms
to
the
existing
context.
Duplicate
context
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
s
<em class="rfc2119" title="must">
must
</em>
be
overridden
using
a
last-defined-overrides
mechanism.
</p>
<div class="example"><div class="example-title"><span>Example 5</span>: Scoped contexts within node definitions</div><pre class="example">{
  <span class="diff">&quot;@context&quot;:
<ins class="diff-new">  {
    &quot;name&quot;: &quot;http://example.com/person#name&quot;,
    &quot;details&quot;: &quot;http://example.com/person#details&quot;
  },</span>
  &quot;<span class="diff">name</span>&quot;: &quot;Markus Lanthaler&quot;,
  ...
  &quot;details&quot;:
  {
</ins>    <span class="diff">&quot;@context&quot;: {<ins class="diff-new">
      &quot;name&quot;: &quot;http://example.com/organization#name&quot;
    },</span>
    &quot;<span class="diff">name</span>&quot;: &quot;Graz University of Technology&quot;
  }
}
</ins></pre></div><p><ins class="diff-new">
In
the
example
above,
the
</ins><code><ins class="diff-new">
name
</ins></code><ins class="diff-new">
prefix
is
overridden
in
the
more
deeply
nested
</ins><code><ins class="diff-new">
details
</ins></code><ins class="diff-new">
structure.
Note
that
this
is
rarely
a
good
authoring
practice
and
is
typically
used
when
there
exist
legacy
applications
that
depend
on
the
specific
structure
of
the
</ins><a class="tref internalDFN" title="json_object" href="#dfn-json_object"><ins class="diff-new">
JSON
object
</ins></a>.</p>
<div class="note">
<div class="note-title">
<span>
Note
</span>
</div>
<p class="">
If
a
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
is
re-defined
within
a
context,
all
previous
rules
associated
with
the
previous
definition
are
removed.
A
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
defined
in
a
previous
context
<em class="rfc2119" title="must">
must
</em>
be
removed,
if
it
is
re-defined
to
<code>
null
</code>.
</p>
</div>
<p>
The
set
of
contexts
defined
within
a
specific
<del class="diff-old">subject
</del>
<a class="tref internalDFN" title="node_definition" href="#dfn-node_definition">
<ins class="diff-chg">node
</ins>
definition
</a>
are
referred
to
as
<dfn title="local_context" id="dfn-local_context">
local
context
</dfn>
s.
Setting
the
context
to
<code>
null
</code>
effectively
<del class="diff-old">sets
</del>
<ins class="diff-chg">resets
</ins>
the
<del class="diff-old">local
</del>
<a class="tref internalDFN" title="active_context" href="#dfn-active_context">
<ins class="diff-chg">active
</ins>
context
</a>
to
<del class="diff-old">the
initial
context
(further
explained
in
the
JSON-LD
API,
Appendix
A,
Initial
Context
[
JSON-LD-API
]
).
</del>
<ins class="diff-chg">an
empty
context.
</ins>
The
<dfn title="active_context" id="dfn-active_context">
active
context
</dfn>
refers
to
the
accumulation
of
<a class="tref internalDFN" title="local_context" href="#dfn-local_context">
local
context
</a>
s
that
are
in
scope
at
a
specific
point
within
the
document.
The
following
example
specifies
an
external
context
and
then
layers
a
local
context
on
top
of
the
external
context:
</p>
<del class="diff-old">{
</del>
<div class="example"><div class="example-title"><span>Example 6</span>: Combining external and local contexts</div><pre class="example">{
  <span class="diff">&quot;@context&quot;: [
    &quot;http://json-ld.org/contexts/person.jsonld&quot;,
    {
      &quot;pic&quot;: &quot;http://xmlns.com/foaf/0.1/depiction&quot;
    }
  ],</span>
  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;,
  <span class="diff">&quot;pic&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;</span>
}
</pre>
</div>
<div class="note">
<div class="note-title">
<span>
Note
</span>
</div>
<p class="">
To
ensure
the
best
possible
performance,
it
is
a
best
practice
to
put
the
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>
definition
at
the
top
of
the
JSON-LD
document.
If
it
isn't
listed
first,
processors
have
to
save
each
key-value
pair
until
the
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>
is
processed.
This
creates
a
memory
and
complexity
burden
for
certain
types
of
low-memory
footprint
JSON-LD
processors.
</p>
</div>
<div class="note">
<div class="note-title">
<span>
Note
</span>
</div>
<p class="">
The
<code>
null
</code>
value
is
processed
in
a
special
way
in
JSON-LD.
Unless
otherwise
specified,
a
JSON-LD
processor
<em class="rfc2119" title="must">
must
</em>
act
as
if
a
key-value
pair
in
the
body
of
a
JSON-LD
document
was
never
declared
when
the
value
equals
<em>
null
</em>.
If
<code>
@value
</code>,
<code>
@list
</code>,
or
<code>
@set
</code>
is
set
to
<em>
null
</em>
in
expanded
form,
then
the
entire
<a class="tref internalDFN" title="json_object" href="#dfn-json_object">
JSON
object
</a>
is
ignored.
If
<code>
@context
</code>
is
set
to
<em>
null
</em>,
the
<a class="tref internalDFN" title="active_context" href="#dfn-active_context">
active
context
</a>
is
reset
and
when
used
within
a
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>,
it
removes
any
definition
associated
with
the
key,
unless
otherwise
specified.
</p>
</div>
</section>
<section id="from-json-to-json-ld">
<h3>
<span class="secno">
<del class="diff-old">3.1.3
</del>
<ins class="diff-chg">3.6
</ins>
</span>
From
JSON
to
JSON-LD
</h3>
<p>
If
a
set
of
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
s
such
as,
<strong>
name
</strong>,
<strong>
homepage
</strong>,
and
<strong>
depiction
</strong>,
are
defined
in
a
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>,
and
that
context
is
used
to
resolve
the
names
in
<a class="tref internalDFN" title="json_object" href="#dfn-json_object">
JSON
objects
</a>,
machines
are
able
to
automatically
expand
the
terms
to
something
meaningful
and
unambiguous,
like
this:
</p>
<del class="diff-old">{
</del>
<div class="example"><div class="example-title"><span>Example 7</span>: Expanded terms</div><pre class="example">{
  &quot;<span class="diff">http://xmlns.com/foaf/0.1/name</span>&quot;: &quot;Manu Sporny&quot;,
  &quot;<span class="diff">http://xmlns.com/foaf/0.1/homepage</span>&quot;: &quot;http://manu.sporny.org&quot;
  &quot;<span class="diff">http://xmlns.com/foaf/0.1/depiction</span>&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;
}
</pre>
</div>
<p>
Doing
this
allows
JSON
to
be
unambiguously
machine-readable
without
requiring
developers
to
drastically
change
their
workflow.
</p>
<div class="note">
<div class="note-title">
<span>
Note
</span>
</div>
<p class="">
The
example
above
does
not
use
the
<code>
@id
</code>
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
keyword
</a>
to
<del class="diff-old">set
the
subject
of
</del>
<ins class="diff-chg">identify
</ins>
the
node
being
described
above.
This
type
of
node
is
called
an
<a class="tref internalDFN" title="unlabeled_node" href="#dfn-unlabeled_node">
unlabeled
node
</a>.
It
is
advised
that
all
nodes
described
in
JSON-LD
are
given
unique
identifiers
via
the
<code>
@id
</code>
keyword
unless
the
data
is
not
intended
to
be
linked
to
from
other
data
sets.
</p>
</div>
<p>
A
<a class="tref internalDFN" title="json_object" href="#dfn-json_object">
JSON
object
</a>
used
to
define
property
values
is
called
a
<del class="diff-old">subject
</del>
<a class="tref internalDFN" title="node_definition" href="#dfn-node_definition">
<ins class="diff-chg">node
</ins>
definition
</a>.
<del class="diff-old">Subject
</del>
<a class="tref internalDFN" title="node_definition" href="#dfn-node_definition">
<ins class="diff-chg">Node
</ins>
definitions
</a>
do
not
require
an
<code>
@id
</code>.
<del class="diff-old">Subject
</del>
<a class="tref internalDFN" title="node_definition" href="#dfn-node_definition">
<ins class="diff-chg">Node
</ins>
definitions
</a>
that
do
not
contain
an
<code>
@id
</code>
are
known
as
an
<a class="tref internalDFN" title="unlabeled_node" href="#dfn-unlabeled_node">
unlabeled
nodes
</a>.
</p>
</section>
<section id="iris">
<h3>
<span class="secno">
<del class="diff-old">3.2
</del>
<ins class="diff-chg">3.7
</ins>
</span>
IRIs
</h3>
<p>
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<del class="diff-old">IRI
</del>
<ins class="diff-chg">IRIs
</ins>
</a>
<del class="diff-old">s
</del>
are
fundamental
to
<a class="tref internalDFN" title="linked_data" href="#dfn-linked_data">
Linked
Data
</a>
as
that
is
how
most
<del class="diff-old">subject
</del>
<a class="tref internalDFN" title="node" href="#dfn-node">
<ins class="diff-chg">nodes
</ins>
</a>
<del class="diff-old">s,
</del>
<ins class="diff-chg">s
and
</ins>
all
<a class="tref internalDFN" title="property" href="#dfn-property">
properties
</a>
<del class="diff-old">and
many
object
s
</del>
are
identified.
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
s
can
be
expressed
in
a
variety
of
different
ways
in
JSON-LD.
</p>
<p>
<ins class="diff-new">An
</ins><dfn title="iri" id="dfn-iri"><abbr title="Internationalized Resource Identifier"><ins class="diff-new">
IRI
</ins></abbr></dfn><ins class="diff-new">
(an
Internationalized
Resource
Identifier)
is
described
in
[
</ins><cite><a class="bibref" href="#bib-RFC3987"><ins class="diff-new">
RFC3987
</ins></a></cite><ins class="diff-new">
])
and
the
use
with
JSON-LD
conforms
to
the
definition
of
</ins><cite><a href="http://www.w3.org/TR/rdf11-concepts/#dfn-iri"><abbr title="Internationalized Resource Identifier"><ins class="diff-new">
IRI
</ins></abbr></a></cite><ins class="diff-new">
in
[
</ins><cite><a class="bibref" href="#bib-RDF-CONCEPTS"><ins class="diff-new">
RDF-CONCEPTS
</ins></a></cite><ins class="diff-new">
].
</ins></p>
<ol>
<li>
Except
within
a
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>
definition,
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
s
in
the
key
position
in
a
<a class="tref internalDFN" title="json_object" href="#dfn-json_object">
JSON
object
</a>
that
have
a
mapping
<del class="diff-old">to
an
absolute
</del>
<ins class="diff-chg">or
a
vocabulary
base
</ins><a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
<del class="diff-old">or
another
term
</del>
in
the
<a class="tref internalDFN" title="active_context" href="#dfn-active_context">
active
context
</a>
are
expanded
to
an
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
by
JSON-LD
processors.
</li>
<li>
An
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
is
generated
for
the
<a class="tref internalDFN" title="string" href="#dfn-string">
string
</a>
value
specified
using
<code>
@id
</code>
or
<code>
@type
</code>.
</li>
<li>
An
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
is
generated
for
the
<a class="tref internalDFN" title="string" href="#dfn-string">
string
</a>
value
of
any
key
for
which
there
are
<a class="tref internalDFN" title="coercion" href="#dfn-coercion">
coercion
</a>
rules
in
effect
that
identify
the
value
as
an
<code>
@id
</code>.
</li>
</ol>
<p>
IRIs
may
be
represented
as
an
<a class="tref internalDFN" title="absolute_iri" href="#dfn-absolute_iri">
absolute
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>,
a
<a class="tref internalDFN" title="relative_iri" href="#dfn-relative_iri">
relative
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>,
a
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>,
<del class="diff-old">or
</del>
a
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
compact
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
<del class="diff-old">.
</del>
</a>,
<ins class="diff-chg">or
as
a
value
relative
to
</ins><code><ins class="diff-chg">
@vocab
</ins></code>.
</p>
<p>
An
<dfn title="absolute_iri" id="dfn-absolute_iri">
absolute
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</dfn>
is
defined
in
[
<cite>
<a class="bibref" href="#bib-RFC3987">
RFC3987
</a>
</cite>
]
containing
a
<em>
scheme
</em>
along
with
<em>
path
</em>
and
optional
<em>
query
</em>
and
<em>
fragment
</em>
segments.
A
<dfn title="relative_iri" id="dfn-relative_iri">
relative
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</dfn>
is
an
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
that
is
relative
to
some
other
<a class="tref internalDFN" title="absolute_iri" href="#dfn-absolute_iri">
absolute
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>.
In
JSON-LD
all
<a class="tref internalDFN" title="relative_iri" href="#dfn-relative_iri">
relative
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
s
are
resolved
relative
to
the
<dfn title="base_iri" id="dfn-base_iri">
base
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</dfn>
associated
with
the
document
(typically,
the
directory
that
contains
the
document
or
the
document
itself).
</p>
<p>
IRIs
can
be
expressed
directly
in
the
key
position
like
so:
</p>
<del class="diff-old">{
</del>
<div class="example"><div class="example-title"><span>Example 8</span>: IRI as a key</div><pre class="example">{
...
  &quot;<span class="diff">http://xmlns.com/foaf/0.1/name</span>&quot;: &quot;Manu Sporny&quot;,
...
}
</pre>
</div>
<p>
In
the
example
above,
the
key
<code>
http://xmlns.com/foaf/0.1/name
</code>
is
interpreted
as
an
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
because
it
contains
a
colon
(
<code>:
</code>
)
and
the
'http'
<a class="tref internalDFN" title="prefix" href="#dfn-prefix">
prefix
</a>
does
not
exist
in
the
context.
</p>
<p>
Term
expansion
occurs
for
IRIs
if
the
value
matches
a
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
defined
within
the
<a class="tref internalDFN" title="active_context" href="#dfn-active_context">
active
context
</a>:
</p>
<del class="diff-old">{
</del>
<div class="example"><div class="example-title"><span>Example 9</span>: Term expansion from context definition</div><pre class="example">{
  &quot;<span class="diff">@context</span>&quot;:
  {
    &quot;<span class="diff">name</span>&quot;: &quot;<span class="diff">http://xmlns.com/foaf/0.1/name</span>&quot;
...
  },
  &quot;<span class="diff">name</span>&quot;: &quot;Manu Sporny&quot;,
  &quot;status&quot;: &quot;trollin'&quot;,
...
}
</pre>
</div>
<p>
<a class="tref internalDFN" title="term" href="#dfn-term">
Term
</a>
s
are
case
sensitive,
and
<em class="rfc2119" title="must">
must
</em>
be
matched
using
a
case-sensitive
comparison.
</p>
<p>
JSON
keys
that
do
not
expand
to
an
absolute
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
are
ignored,
or
removed
in
some
cases,
by
the
[
<cite>
<a class="bibref" href="#bib-JSON-LD-API">
JSON-LD-API
</a>
</cite>
].
However,
JSON
keys
that
do
not
include
a
mapping
in
the
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>
are
still
considered
valid
expressions
in
JSON-LD
documents
-
the
keys
just
don't
have
any
machine-readable,
semantic
meaning.
</p>
<p>
<a class="tref internalDFN" title="prefix" href="#dfn-prefix">
Prefix
</a>
es
are
expanded
when
the
form
of
the
value
is
a
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
compact
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
represented
as
a
<code>
prefix:suffix
</code>
combination,
and
the
prefix
matches
a
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
defined
within
the
<a class="tref internalDFN" title="active_context" href="#dfn-active_context">
active
context
</a>:
</p>
<del class="diff-old">{
</del>
<div class="example"><div class="example-title"><span>Example 10</span>: Prefix expansion</div><pre class="example">{
  &quot;<span class="diff">@context</span>&quot;:
  {
    &quot;<span class="diff">foaf</span>&quot;: &quot;<span class="diff">http://xmlns.com/foaf/0.1/</span>&quot;
...
  },
  &quot;<span class="diff">foaf:name</span>&quot;: &quot;Manu Sporny&quot;,
...
}
</pre>
</div>
<p>
<code>
foaf:name
</code>
above
will
automatically
expand
out
to
the
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
<code>
http://xmlns.com/foaf/0.1/name
</code>.
See
<a href="#compact-iris" class="sec-ref">
<span class="secno">
<ins class="diff-chg">4.1
</ins></span><span class="sec-title">
Compact
IRIs
</span>
</a>
for
more
details.
</p>
<p>
<ins class="diff-new">If
the
</ins><code><ins class="diff-new">
@vocab
</ins></code><ins class="diff-new">
is
set,
all
keys
that
do
not
match
a
</ins><a class="tref internalDFN" title="term" href="#dfn-term"><ins class="diff-new">
term
</ins></a><ins class="diff-new">
or
a
</ins><a class="tref internalDFN" title="prefix" href="#dfn-prefix"><ins class="diff-new">
prefix
</ins></a><ins class="diff-new">
are
It
is
often
common
that
all
types
and
properties
come
from
the
same
vocabulary.
JSON-LD's
</ins><code><ins class="diff-new">
@vocab
</ins></code><ins class="diff-new">
keyword
allows
to
set
a
base
</ins><a class="tref internalDFN" title="iri" href="#dfn-iri"><abbr title="Internationalized Resource Identifier"><ins class="diff-new">
IRI
</ins></abbr></a><ins class="diff-new">
to
be
used
for
all
properties
and
types
that
that
do
not
match
a
</ins><a class="tref internalDFN" title="term" href="#dfn-term"><ins class="diff-new">
term
</ins></a>,<ins class="diff-new">
a
</ins><a class="tref internalDFN" title="prefix" href="#dfn-prefix"><ins class="diff-new">
prefix
</ins></a>,<ins class="diff-new">
or
an
</ins><a class="tref internalDFN" title="absolute_iri" href="#dfn-absolute_iri"><ins class="diff-new">
absolute
</ins><abbr title="Internationalized Resource Identifier"><ins class="diff-new">
IRI
</ins></abbr></a><ins class="diff-new">
(i.e.,
do
not
contain
a
colon).
The
</ins><code><ins class="diff-new">
@vocab
</ins></code><ins class="diff-new">
mapping
</ins><em class="rfc2119" title="must"><ins class="diff-new">
must
</ins></em><ins class="diff-new">
have
a
value
of
a
simple
string
with
the
lexical
form
of
an
absolute
</ins><abbr title="Internationalized Resource Identifier"><ins class="diff-new">
IRI
</ins></abbr>.</p><div class="example"><div class="example-title"><span>Example 11</span>: Vocabulary base IRI</div><pre class="example">{  <span class="diff">&quot;@context&quot;: {<ins class="diff-new">
    &quot;@vocab&quot;: &quot;http://xmlns.com/foaf/1.0/&quot;
  },</span>
  &quot;@type&quot;: <span class="diff">&quot;Person&quot;</span>,
</ins>  <span class="diff">&quot;name&quot;</span>: &quot;Manu Sporny&quot;,<ins class="diff-new">
}
</ins></pre></div><p>
An
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
is
generated
when
a
<a class="tref internalDFN" title="json_object" href="#dfn-json_object">
JSON
object
</a>
is
used
in
the
value
position
that
contains
an
<code>
@id
</code>
keyword:
</p>
<del class="diff-old">{
</del>
<div class="example"><div class="example-title"><span>Example 12</span>: Expanded IRI definition</div><pre class="example">{
...
  &quot;homepage&quot;: { &quot;<span class="diff">@id</span>&quot;: &quot;http://manu.sporny.org&quot; }
...
}
</pre>
</div>
<div class="note">
<div class="note-title">
<span>
Note
</span>
</div>
<p class="">
Specifying
a
<a class="tref internalDFN" title="json_object" href="#dfn-json_object">
JSON
object
</a>
with
an
<code>
@id
</code>
key
is
used
to
identify
that
<del class="diff-old">object
</del>
<a class="tref internalDFN" title="node" href="#dfn-node">
<ins class="diff-chg">node
</ins></a>
using
an
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>.
When
the
object
has
only
the
<code>
@id
</code>,
it
is
called
a
<del class="diff-old">subject
</del>
<a class="tref internalDFN" title="node_reference" href="#dfn-node_reference">
<ins class="diff-chg">node
</ins>
reference
</a>.
This
facility
<em class="rfc2119" title="may">
may
</em>
also
be
used
to
link
to
another
<del class="diff-old">subject
</del>
<a class="tref internalDFN" title="node_definition" href="#dfn-node_definition">
<ins class="diff-chg">node
</ins>
definition
</a>
using
a
mechanism
called
<a class="tref internalDFN" title="embedding" href="#dfn-embedding">
embedding
</a>,
which
is
covered
in
the
section
titled
<a href="#embedding" class="sec-ref">
<span class="secno">
<ins class="diff-chg">4.10
</ins></span><span class="sec-title">
Embedding
</span>
</a>.
</p>
</div>
<p>
If
type
<a class="tref internalDFN" title="coercion" href="#dfn-coercion">
coercion
</a>
rules
are
specified
in
the
<code>
@context
</code>
for
a
particular
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
or
property
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>,
an
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
is
generated:
</p>
<div class="example"><div class="example-title"><span>Example 13</span>: Type coercion</div><pre class="example">{<span class="diff">
  &quot;@context&quot;:
  {
    ...
    &quot;homepage&quot;:
    {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/homepage&quot;,
      &quot;@type&quot;: &quot;@id&quot;
    }
    ...
  }</span>
...
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;,
...
}
</pre>
</div>
<p>
In
the
example
above,
even
though
the
value
<code>
http://manu.sporny.org/
</code>
is
expressed
as
a
JSON
<a class="tref internalDFN" title="string" href="#dfn-string">
string
</a>,
the
type
<a class="tref internalDFN" title="coercion" href="#dfn-coercion">
coercion
</a>
rules
will
transform
the
value
into
an
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
when
processed
by
a
JSON-LD
Processor.
</p>
</section>
<section id="node-identifiers">
<h3>
<span class="secno">
<del class="diff-old">3.3
</del>
<ins class="diff-chg">3.8
</ins>
</span>
<del class="diff-old">Identifying
the
Subject
</del>
<ins class="diff-chg">Node
Identifiers
</ins>
</h3>
<p>
To
be
able
to
externally
reference
nodes
in
a
graph,
it
is
important
that
each
node
has
an
unambiguous
identifier.
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
s
are
a
fundamental
concept
of
<a class="tref internalDFN" title="linked_data" href="#dfn-linked_data">
Linked
Data
</a>,
and
nodes
should
have
a
de-referencable
identifier
used
to
name
and
locate
them.
For
nodes
to
be
truly
linked,
de-referencing
the
identifier
should
result
in
a
representation
of
that
node
(for
example,
using
a
URL
to
retrieve
a
web
page).
Associating
an
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
with
a
node
tells
an
application
that
the
returned
document
contains
a
description
of
the
node
requested.
</p>
<p>
JSON-LD
documents
may
also
contain
descriptions
of
other
nodes,
so
it
is
necessary
to
be
able
to
uniquely
identify
each
node
which
may
be
externally
referenced.
</p>
<p>
<del class="diff-old">A
subject
</del>
<ins class="diff-chg">The
node
</ins>
of
a
<a class="tref internalDFN" title="json_object" href="#dfn-json_object">
JSON
object
</a>
is
<del class="diff-old">a
node
</del>
identified
using
the
<code>
@id
</code>
<del class="diff-old">key.
The
subject
is
the
first
piece
of
information
needed
by
the
JSON-LD
processor
in
order
to
create
the
(subject,
property,
object)
tuple,
also
known
as
a
triple.
</del>
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
<ins class="diff-chg">keyword
</ins></a>:
</p>
<del class="diff-old">{
</del>
<div class="example"><div class="example-title"><span>Example 14</span>: Identifying a node</div><pre class="example">{
  &quot;@context&quot;:
  {
    ...
    &quot;homepage&quot;:
    {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/homepage&quot;,
      &quot;@type&quot;: &quot;@id&quot;
    }
    ...
  },
  &quot;<span class="diff">@id</span>&quot;: &quot;<span class="diff">http://example.org/people#joebob</span>&quot;,
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;,
...
}
</pre>
</div>
<p>
The
example
above
<del class="diff-old">would
set
the
subject
to
</del>
<ins class="diff-chg">contains
a
node
identified
by
</ins>
the
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
<code>
http://example.org/people#joebob
</code>.
</p>
<p>
A
<a class="tref internalDFN" title="json_object" href="#dfn-json_object">
JSON
object
</a>
used
to
define
property
values
is
called
a
<del class="diff-old">subject
</del>
<a class="tref internalDFN" title="node_definition" href="#dfn-node_definition">
<ins class="diff-chg">node
</ins>
definition
</a>.
<del class="diff-old">Subject
</del>
<a class="tref internalDFN" title="node_definition" href="#dfn-node_definition">
<ins class="diff-chg">Node
</ins>
definitions
</a>
do
not
require
an
<code>
@id
</code>.
A
<del class="diff-old">subject
</del>
<a class="tref internalDFN" title="node_definition" href="#dfn-node_definition">
<ins class="diff-chg">node
</ins>
definition
</a>
that
does
not
contain
an
<code>
@id
</code>
property
defines
properties
of
an
<a class="tref internalDFN" title="unlabeled_node" href="#dfn-unlabeled_node">
unlabeled
node
</a>.
<a class="tref internalDFN" title="node_definition" href="#dfn-node_definition">
<ins class="diff-new">Node
definitions
</ins></a><em class="rfc2119" title="may"><ins class="diff-new">
may
</ins></em><ins class="diff-new">
be
spread
among
different
parts
of
a
document
or
even
between
different
documents.
</ins>
</p>
<div class="note">
<div class="note-title">
<span>
Note
</span>
</div>
<p class="">
To
ensure
the
best
possible
performance,
when
possible,
it
is
a
best
practice
to
put
JSON-LD
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
keyword
</a>
s,
such
as
<code>
@id
</code>
and
<code>
@context
</code>
before
other
key-value
pairs
in
a
<a class="tref internalDFN" title="json_object" href="#dfn-json_object">
JSON
object
</a>.
However,
keys
in
a
<a class="tref internalDFN" title="json_object" href="#dfn-json_object">
JSON
object
</a>
are
not
ordered,
so
processors
<em class="rfc2119" title="must not">
must
not
</em>
depend
on
key
ordering.
If
keywords
are
not
listed
first,
processors
have
to
save
each
key-value
pair
until
at
least
the
<code>
@context
</code>
and
the
<code>
@id
</code>
are
processed.
Not
specifying
those
keywords
first
creates
a
memory
and
complexity
burden
for
low-memory
footprint
processors,
forcing
them
to
use
more
memory
and
computing
cycles
than
necessary.
</p>
</div>
</section>
<section id="specifying-the-type">
<h3>
<span class="secno">
<del class="diff-old">3.4
</del>
<ins class="diff-chg">3.9
</ins>
</span>
Specifying
the
Type
</h3>
<p>
The
type
of
a
particular
<del class="diff-old">subject
</del>
<ins class="diff-chg">node
</ins>
can
be
specified
using
the
<code>
@type
</code>
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
keyword
</a>.
<del class="diff-old">Specifying
the
type
in
this
way
will
generate
a
triple
of
the
form
(subject,
type,
type-
IRI
).
</del>
To
be
considered
<a class="tref internalDFN" title="linked_data" href="#dfn-linked_data">
Linked
Data
</a>,
types
<em class="rfc2119" title="must">
must
</em>
be
uniquely
identified
by
an
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>.
</p>
<del class="diff-old">{
</del>
<div class="example"><div class="example-title"><span>Example 15</span>: Specifying the type for a node</div><pre class="example">{
...
  &quot;@id&quot;: &quot;http://example.org/people#joebob&quot;,
  &quot;<span class="diff">@type</span>&quot;: &quot;<span class="diff">http://xmlns.com/foaf/0.1/Person</span>&quot;,
...
}
</pre>
</div>
<p>
<ins class="diff-new">A
node
can
be
assigned
more
than
one
type
by
using
the
following
markup
pattern:
</ins></p><div class="example"><div class="example-title"><span>Example 16</span>: Specifying multiple types for a node</div><pre class="example">{<ins class="diff-new">
...
  &quot;@id&quot;: &quot;http://example.org/places#BrewEats&quot;,
  &quot;<span class="diff">@type</span>&quot;: <span class="diff">[&quot;http://schema.org/Restaurant&quot;, &quot;http://schema.org/Brewery&quot;]</span>
...
}
</ins></pre>
</div>
</section>
<section id="string-internationalization">
<h3>
<span class="secno">
<del class="diff-old">3.5
</del>
<ins class="diff-chg">3.10
</ins>
</span>
String
Internationalization
</h3>
<p>
At
times,
it
is
important
to
annotate
a
<a class="tref internalDFN" title="string" href="#dfn-string">
string
</a>
with
its
language.
In
JSON-LD
this
is
possible
in
a
variety
of
ways.
Firstly,
it
is
possible
to
define
a
default
language
for
a
JSON-LD
document
by
setting
the
<code>
@language
</code>
key
in
the
<code>
@context
</code>
or
in
a
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
definition:
</p>
<del class="diff-old">{
</del>
<div class="example"><div class="example-title"><span>Example 17</span>: String Internationalization</div><pre class="example">{
  <span class="diff">&quot;@context&quot;:
  {
    ...
    &quot;@language&quot;: &quot;ja&quot;
  },</span>
  &quot;name&quot;: <span class="diff">&quot;花澄&quot;</span>,
  &quot;occupation&quot;: <span class="diff">&quot;科学者&quot;</span>
}
</pre>
</div>
<p>
The
example
above
would
associate
the
<code>
ja
</code>
language
code
with
the
two
<a class="tref internalDFN" title="string" href="#dfn-string">
string
</a>
s
<em>
花澄
</em>
and
<em>
科学者
</em>.
Languages
<em class="rfc2119" title="must">
must
</em>
be
well-formed
language
tags
according
to
[
<cite>
<a class="bibref" href="#bib-BCP47">
BCP47
</a>
</cite>
].
</p>
<p>
It
is
possible
to
override
the
default
language
by
using
the
expanded
form
of
a
value:
</p>
<del class="diff-old">{
</del>
<div class="example"><div class="example-title"><span>Example 18</span>: Expanded value with language</div><pre class="example">{
  &quot;@context&quot;: {
    ...
    &quot;@language&quot;: &quot;ja&quot;
  },
  &quot;name&quot;: &quot;花澄&quot;,
  &quot;occupation&quot;: <span class="diff">{
    &quot;@value&quot;: &quot;Scientist&quot;,
    &quot;@language&quot;: &quot;en&quot;
  }</span>
}
</pre>
</div>
<p>
It
is
also
possible
to
override
the
default
language
or
specify
a
plain
value
by
omitting
the
<code>
@language
</code>
tag
or
setting
it
to
<code>
null
</code>
when
expressing
the
expanded
value:
</p>
<del class="diff-old">{
</del>
<div class="example"><div class="example-title"><span>Example 19</span>: Expanded value to remove language</div><pre class="example">{
  &quot;@context&quot;: {
    ...
    &quot;@language&quot;: &quot;ja&quot;
  },
  &quot;name&quot;: <span class="diff">{
    &quot;@value&quot;: &quot;Frank&quot;
  },</span>
  &quot;occupation&quot;: <span class="diff"> {
    &quot;@value&quot;: &quot;Ninja&quot;,
    &quot;@language&quot;: &quot;en&quot;
  }</span>,
  &quot;speciality&quot;: &quot;手裏剣&quot;
}
</pre>
</div>
<div class="note">
<div class="note-title">
<span>
Note
</span>
</div>
<p class="">
Please
note
that
language
associations
<em class="rfc2119" title="must">
must
</em>
only
be
applied
to
plain
literal
<a class="tref internalDFN" title="string" href="#dfn-string">
string
</a>
s.
That
is,
<a class="tref internalDFN" title="typed_value" href="#dfn-typed_value">
typed
value
</a>
s
or
values
that
are
subject
to
<del class="diff-old">type
coercion
</del>
<a href="#type-coercion" class="sec-ref">
<span class="secno">
<ins class="diff-chg">4.6
</ins></span><span class="sec-title"><ins class="diff-chg">
Type
Coercion
</ins></span>
</a>
won't
be
language
tagged.
</p>
</div>
<p>
To
clear
the
default
language
for
a
subtree,
<code>
@language
</code>
can
be
set
to
<code>
null
</code>
in
a
<a class="tref internalDFN" title="local_context" href="#dfn-local_context">
local
context
</a>
as
follows:
</p>
<del class="diff-old">{
</del>
<div class="example"><div class="example-title"><span>Example 20</span>: Clearing default language</div><pre class="example">{
  &quot;@context&quot;: {
    ...
    &quot;@language&quot;: &quot;ja&quot;
  },
  &quot;name&quot;: &quot;花澄&quot;,
  &quot;details&quot;: {
<span class="diff">    &quot;@context&quot;: {
      &quot;@language&quot;: null
    },</span>
    &quot;occupation&quot;: &quot;Ninja&quot;
  }
}
</pre>
</div>
<div class="note">
<div class="note-title">
<span>
Note
</span>
</div>
<p class="">
JSON-LD
allows
one
to
associate
language
information
with
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
s.
See
<a href="#expanded-term-definition" class="sec-ref">
<span class="secno">
<ins class="diff-chg">4.5
</ins></span><span class="sec-title">
Expanded
Term
Definition
</span>
</a>
for
more
details.
</p>
</div>
</section>
<section id="json-ld-syntax">
<h3>
<span class="secno">
<del class="diff-old">3.6
</del>
<ins class="diff-chg">3.11
</ins>
</span>
JSON-LD
Syntax
</h3>
<p>
A
JSON-LD
document
is
first,
and
foremost,
a
JSON
document
(as
defined
in
[
<cite>
<del class="diff-old">RFC5988
</del>
<a class="bibref" href="#bib-RFC4627">
<ins class="diff-chg">RFC4627
</ins>
</a>
</cite>
]),
and
any
syntactically
correct
JSON
document
<em class="rfc2119" title="must">
must
</em>
be
processed
by
a
conforming
JSON-LD
processor.
However,
JSON-LD
describes
a
specific
syntax
to
use
for
expressing
Linked
Data.
This
includes
the
use
of
specific
keywords,
as
identified
in
<a href="#syntax-tokens-and-keywords" class="sec-ref">
<span class="secno">
<ins class="diff-chg">3.4
</ins></span><span class="sec-title">
Syntax
Tokens
and
Keywords
</span>
</a>
for
expressing
<del class="diff-old">subject
</del>
<a title="node definition">
<ins class="diff-chg">node
</ins>
definitions
</a>,
values,
and
the
<a href="#dfn-context" class="internalDFN">
context
</a>.
See
<del class="diff-old">Appendix
A
</del>
<a href="#json-ld-grammar" class="sec-ref">
<span class="secno">
<ins class="diff-chg">A.
</ins></span><span class="sec-title"><ins class="diff-chg">
JSON-LD
Grammar
</ins></span>
</a>
for
authoring
guidelines
and
a
BNF
description
of
JSON-LD.
</p>
</section>
</section>
<section id="advanced-concepts">
<h2>
<span class="secno">
4.
</span>
Advanced
Concepts
</h2>
<em>
This
section
is
normative.
</em>
<p>
JSON-LD
has
a
number
of
features
that
provide
functionality
above
and
beyond
the
core
functionality
described
above.
The
following
section
describes
this
advanced
functionality
in
more
detail.
</p>
<section id="compact-iris">
<h3>
<span class="secno">
4.1
</span>
Compact
IRIs
</h3>
<p>
<a class="tref internalDFN" title="term" href="#dfn-term">
Term
</a>
s
in
<a class="tref internalDFN" title="linked_data" href="#dfn-linked_data">
Linked
Data
</a>
documents
may
draw
from
a
number
of
different
<a class="tref internalDFN" title="vocabulary" href="#dfn-vocabulary">
vocabularies
</a>.
At
times,
declaring
every
single
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
that
a
document
uses
can
require
the
developer
to
declare
tens,
if
not
hundreds
of
potential
<a class="tref internalDFN" title="vocabulary" href="#dfn-vocabulary">
vocabulary
</a>
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
s
that
are
used
across
an
application.
This
is
a
concern
for
at
least
two
reasons:
the
first
is
the
cognitive
load
on
the
developer
of
remembering
all
of
the
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
s,
and
the
second
is
the
serialized
size
of
the
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>
if
it
is
specified
inline.
In
order
to
address
these
issues,
the
concept
of
a
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
compact
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
is
introduced.
</p>
<p>
A
<dfn title="compact_iri" id="dfn-compact_iri">
compact
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</dfn>
is
a
way
of
expressing
an
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
using
a
<em>
prefix
</em>
and
<em>
suffix
</em>
separated
by
a
colon
(
<code>:
</code>
)
which
is
similar
to
the
<cite>
<a href="http://www.w3.org/TR/rdfa-core/#s_curies">
CURIE
Syntax
</a>
</cite>
in
[
<cite>
<a class="bibref" href="#bib-RDFA-CORE">
RDFA-CORE
</a>
</cite>
].
The
<dfn title="prefix" id="dfn-prefix">
prefix
</dfn>
is
a
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
taken
from
the
<a class="tref internalDFN" title="active_context" href="#dfn-active_context">
active
context
</a>
and
is
a
short
string
identifying
a
particular
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
in
a
JSON-LD
document.
For
example,
the
prefix
<code>
foaf
</code>
may
be
used
as
a
short
hand
for
the
Friend-of-a-Friend
vocabulary,
which
is
identified
using
the
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
<code>
http://xmlns.com/foaf/0.1/
</code>.
A
developer
may
append
any
of
the
FOAF
<a class="tref internalDFN" title="vocabulary" href="#dfn-vocabulary">
vocabulary
</a>
terms
to
the
end
of
the
prefix
to
specify
a
short-hand
version
of
the
<a class="tref internalDFN" title="absolute_iri" href="#dfn-absolute_iri">
absolute
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
for
the
<a class="tref internalDFN" title="vocabulary" href="#dfn-vocabulary">
vocabulary
</a>
term.
For
example,
<code>
foaf:name
</code>
would
be
expanded
out
to
the
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
<code>
http://xmlns.com/foaf/0.1/name
</code>.
Instead
of
having
to
remember
and
type
out
the
entire
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>,
the
developer
can
instead
use
the
prefix
in
their
JSON-LD
markup.
</p>
<p>
Terms
are
interpreted
as
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
compact
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
s
if
they
contain
at
least
one
colon
and
the
first
colon
is
not
followed
by
two
slashes
(
<code>
//
</code>,
as
in
<code>
http://example.com
</code>
).
To
generate
the
full
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>,
the
value
is
first
split
into
a
<em>
prefix
</em>
and
<em>
suffix
</em>
at
the
first
occurrence
of
a
colon
(
<code>:
</code>
).
If
the
<a class="tref internalDFN" title="active_context" href="#dfn-active_context">
active
context
</a>
contains
a
term
mapping
for
<em>
prefix
</em>,
an
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
is
generated
by
prepending
the
mapped
<em>
prefix
</em>
to
the
(possibly
empty)
<em>
suffix
</em>
using
textual
concatenation.
If
no
prefix
mapping
is
defined,
the
value
is
interpreted
as
an
<a class="tref internalDFN" title="absolute_iri" href="#dfn-absolute_iri">
absolute
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>.
If
the
prefix
is
an
underscore
(
<code>
_
</code>
),
the
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
remains
unchanged.
This
effectively
means
that
every
term
containing
a
colon
will
be
interpreted
by
a
JSON-LD
processor
as
an
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>.
</p>
<p>
Consider
the
following
example:
</p>
<del class="diff-old">  {
</del>
  <div class="example"><div class="example-title"><span>Example 21</span>: Compact IRIs</div><pre class="example">{
  &quot;@context&quot;:
  {
    <span class="diff">&quot;dc&quot;: &quot;http://purl.org/dc/elements/1.1/&quot;,</span>
    <span class="diff">&quot;ex&quot;: &quot;http://example.org/vocab#&quot;</span>
  },
  &quot;@id&quot;: &quot;http://example.org/library&quot;,
  &quot;@type&quot;: <span class="diff">&quot;ex:Library&quot;</span>,
  <span class="diff">&quot;ex:contains&quot;</span>:
  {
    &quot;@id&quot;: &quot;http://example.org/library/the-republic&quot;,
    &quot;@type&quot;: <span class="diff">&quot;ex:Book&quot;</span>,
    <span class="diff">&quot;dc:creator&quot;</span>: &quot;Plato&quot;,
    <span class="diff">&quot;dc:title&quot;</span>: &quot;The Republic&quot;,
    <span class="diff">&quot;ex:contains&quot;</span>:
    {
      &quot;@id&quot;: &quot;http://example.org/library/the-republic#introduction&quot;,
      &quot;@type&quot;: <span class="diff">&quot;ex:Chapter&quot;</span>,
      <span class="diff">&quot;dc:description&quot;</span>: &quot;An introductory chapter on The Republic.&quot;,
      <span class="diff">&quot;dc:title&quot;</span>: &quot;The Introduction&quot;
    }
  }
}
</pre>
</div>
<p>
In
this
example,
two
different
<a class="tref internalDFN" title="vocabulary" href="#dfn-vocabulary">
vocabularies
</a>
are
referred
to
using
prefixes.
Those
prefixes
are
then
used
as
type
and
property
values
using
the
compact
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
<code>
prefix:suffix
</code>
notation.
</p>
<p>
It's
also
possible
to
use
compact
IRIs
within
the
context
as
shown
in
the
following
example:
</p>
<del class="diff-old">  {
</del>
  <div class="example"><div class="example-title"><span>Example 22</span>: Using vocabularies</div><pre class="example">{
  &quot;@context&quot;:
  {
    &quot;xsd&quot;: &quot;http://www.w3.org/2001/XMLSchema#&quot;,
    &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;,
    <span class="diff">&quot;foaf:homepage&quot;</span>: { &quot;@type&quot;: &quot;@id&quot; },
    &quot;picture&quot;: { &quot;@id&quot;: <span class="diff">&quot;foaf:depiction&quot;</span>, &quot;@type&quot;: &quot;@id&quot; }
  },
  &quot;@id&quot;: &quot;http://me.markus-lanthaler.com/&quot;,
  &quot;@type&quot;: &quot;foaf:Person&quot;,
  &quot;foaf:name&quot;: &quot;Markus Lanthaler&quot;,
  &quot;foaf:homepage&quot;: &quot;http://www.markus-lanthaler.com/&quot;,
  &quot;picture&quot;: &quot;http://twitter.com/account/profile_image/markuslanthaler&quot;
}
</pre>
</div>
</section>
<section id="typed-values">
<h3>
<span class="secno">
4.2
</span>
Typed
Values
</h3>
<p>
A
value
with
an
associated
type,
also
known
as
a
<dfn title="typed_value" id="dfn-typed_value">
typed
value
</dfn>,
is
indicated
by
associating
a
value
with
an
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
which
indicates
the
value's
type.
Typed
values
may
be
expressed
in
JSON-LD
in
<del class="diff-old">two
</del>
<ins class="diff-chg">three
</ins>
ways:
</p>
<ol>
<li>
By
utilizing
the
<code>
@type
</code>
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
keyword
</a>
when
defining
a
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
within
a
<code>
@context
</code>
section.
</li>
<li>
By
utilizing
the
expanded
form
for
specifying
<del class="diff-old">objects.
</del>
<ins class="diff-chg">values.
</ins></li><li><ins class="diff-chg">
By
using
a
native
JSON
type
such
as
</ins><a class="tref internalDFN" title="number" href="#dfn-number"><ins class="diff-chg">
number
</ins></a>,<a class="tref internalDFN" title="true" href="#dfn-true"><ins class="diff-chg">
true
</ins></a>,<ins class="diff-chg">
or
</ins><a class="tref internalDFN" title="false" href="#dfn-false"><ins class="diff-chg">
false
</ins></a>.
</li>
</ol>
<p>
The
first
example
uses
the
<code>
@type
</code>
keyword
to
associate
a
type
with
a
particular
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
in
the
<code>
@context
</code>:
</p>
<del class="diff-old">{
</del>
<div class="example"><div class="example-title"><span>Example 23</span>: Expanded term definition with type coercion</div><pre class="example">{
  <span class="diff">&quot;@context&quot;:
  {
    &quot;modified&quot;:
    {
      &quot;@id&quot;: &quot;http://purl.org/dc/terms/modified&quot;,
      &quot;@type&quot;: &quot;http://www.w3.org/2001/XMLSchema#dateTime&quot;
    }
  },</span>
...
  &quot;modified&quot;: &quot;2010-05-29T14:17:39+02:00&quot;,
...
}
</pre>
</div>
<p>
The
<em>
modified
</em>
key's
value
above
is
automatically
type
coerced
to
a
datetime
value
because
of
the
information
specified
in
the
<code>
@context
</code>.
</p>
<p>
The
second
example
uses
the
expanded
form
of
setting
the
type
information
in
the
body
of
a
JSON-LD
document:
</p>
<del class="diff-old">{
</del>
<div class="example"><div class="example-title"><span>Example 24</span>: Expanded value with type</div><pre class="example">{
  &quot;@context&quot;:
  {
    &quot;modified&quot;:
    {
      &quot;@id&quot;: &quot;http://purl.org/dc/terms/modified&quot;
    }
  },
...
  &quot;modified&quot;:
  <span class="diff">{
    &quot;@value&quot;: &quot;2010-05-29T14:17:39+02:00&quot;,
    &quot;@type&quot;: &quot;http://www.w3.org/2001/XMLSchema#dateTime&quot;
  }</span>
...
}
</pre>
</div>
<p>
Both
examples
above
would
generate
<del class="diff-old">an
object
with
</del>
the
value
<del class="diff-old">of
</del>
<code>
2010-05-29T14:17:39+02:00
</code>
<del class="diff-old">and
</del>
<ins class="diff-chg">with
</ins>
the
type
<del class="diff-old">of
</del>
<code>
http://www.w3.org/2001/XMLSchema#dateTime
</code>.
Note
that
it
is
also
possible
to
use
a
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
or
a
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
compact
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
to
express
the
value
of
a
type.
</p>
<del class="diff-old">Note
</del>
<p>
The
<code>
@type
</code>
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
keyword
</a>
is
also
used
to
associate
a
type
with
a
<del class="diff-old">subject
</del>
<a class="tref internalDFN" title="node" href="#dfn-node">
<ins class="diff-chg">node
</ins>
</a>.
<del class="diff-old">Although
the
same
keyword
is
used
in
both
places,
the
</del>
<ins class="diff-chg">The
</ins>
concept
of
an
<del class="diff-old">object
</del>
<dfn title="node_type" id="dfn-node_type">
<ins class="diff-chg">node
</ins>
type
</dfn>
and
a
<dfn title="value_type" id="dfn-value_type">
value
type
</dfn>
are
different.
This
is
similar
to
object-oriented
programming
languages
where
both
scalar
and
structured
types
use
the
same
class
inheritance
mechanism,
even
though
scalar
types
and
structured
types
are
inherently
different.
</p>
<div class="example"><div class="example-title"><span>Example 25</span>: Example demonstrating the context-sensitivity for @type</div><pre class="example">{
<ins class="diff-new">...
  &quot;@id&quot;: &quot;http://example.org/posts#TripToWestVirginia&quot;,
</ins>  <span class="diff">&quot;@type&quot;: &quot;http://schema.org/BlogPosting&quot;</span>,<ins class="diff-new">
  &quot;modified&quot;:
  {
    &quot;@value&quot;: &quot;2010-05-29T14:17:39+02:00&quot;,
</ins>    <span class="diff">&quot;@type&quot;: &quot;http://www.w3.org/2001/XMLSchema#dateTime&quot;</span><ins class="diff-new">
  }
...
}
</ins></pre>
</div>
<p>
<ins class="diff-chg">The
first
use
of
</ins><code><ins class="diff-chg">
@type
</ins></code><ins class="diff-chg">
associates
a
</ins><a class="tref internalDFN" title="node_type" href="#dfn-node_type"><ins class="diff-chg">
node
type
</ins></a><ins class="diff-chg">
(
</ins><code><ins class="diff-chg">
http://schema.org/BlogPosting
</ins></code><ins class="diff-chg">
)
with
the
</ins><a class="tref internalDFN" title="node" href="#dfn-node"><ins class="diff-chg">
node
</ins></a>,<ins class="diff-chg">
which
is
expressed
using
the
</ins><code><ins class="diff-chg">
@id
</ins></code><a class="tref internalDFN" title="keyword" href="#dfn-keyword"><ins class="diff-chg">
keyword
</ins></a>.<ins class="diff-chg">
The
second
use
of
</ins><code><ins class="diff-chg">
@type
</ins></code><ins class="diff-chg">
associates
a
</ins><a class="tref internalDFN" title="value_type" href="#dfn-value_type"><ins class="diff-chg">
value
type
</ins></a><ins class="diff-chg">
(
</ins><code><ins class="diff-chg">
http://www.w3.org/2001/XMLSchema#dateTime
</ins></code><ins class="diff-chg">
)
with
the
value
expressed
using
the
</ins><code><ins class="diff-chg">
@value
</ins></code><a class="tref internalDFN" title="keyword" href="#dfn-keyword"><ins class="diff-chg">
keyword
</ins></a>.<ins class="diff-chg">
As
a
general
rule,
when
</ins><code><ins class="diff-chg">
@value
</ins></code><ins class="diff-chg">
and
</ins><code><ins class="diff-chg">
@type
</ins></code><ins class="diff-chg">
are
used
in
the
same
</ins><a class="tref internalDFN" title="json_object" href="#dfn-json_object"><ins class="diff-chg">
JSON
object
</ins></a>,<ins class="diff-chg">
the
</ins><code><ins class="diff-chg">
@type
</ins></code><a class="tref internalDFN" title="keyword" href="#dfn-keyword"><ins class="diff-chg">
keyword
</ins></a><ins class="diff-chg">
is
expressing
a
</ins><a class="tref internalDFN" title="value_type" href="#dfn-value_type"><ins class="diff-chg">
value
type
</ins></a>.<ins class="diff-chg">
Otherwise,
the
</ins><code><ins class="diff-chg">
@type
</ins></code><a class="tref internalDFN" title="keyword" href="#dfn-keyword"><ins class="diff-chg">
keyword
</ins></a><ins class="diff-chg">
is
expressing
a
</ins><a class="tref internalDFN" title="node_type" href="#dfn-node_type"><ins class="diff-chg">
node
type
</ins></a>.</p></section><section id="language-tagged-strings">
<h3>
<span class="secno">
4.3
</span>
<del class="diff-old">External
Contexts
</del>
<ins class="diff-chg">Language-tagged
Strings
</ins>
</h3>
<p>
<del class="diff-old">Authors
may
choose
to
declare
JSON-LD
context
s
in
external
documents
to
promote
re-use
of
contexts
as
well
as
reduce
the
size
of
JSON-LD
documents.
In
order
to
use
an
external
context,
</del>
<ins class="diff-chg">A
string
with
</ins>
an
<del class="diff-old">author
must
specify
</del>
<ins class="diff-chg">associated
language,
also
known
as
a
</ins><dfn title="language-tagged_string" id="dfn-language-tagged_string"><ins class="diff-chg">
language-tagged
string
</ins></dfn>,<ins class="diff-chg">
is
indicated
by
associating
a
string
with
</ins>
an
<del class="diff-old">IRI
</del>
<ins class="diff-chg">language
code
as
defined
in
[
</ins><cite>
<a class="bibref" href="#bib-BCP47">
<ins class="diff-new">BCP47
</ins>
</a>
<del class="diff-old">to
a
valid
</del>
</cite>
<ins class="diff-chg">].
Language-tagged
strings
may
be
expressed
in
</ins>
JSON-LD
<del class="diff-old">document.
The
referenced
document
must
have
</del>
<ins class="diff-chg">in
four
ways:
</ins></p><ol><li><ins class="diff-chg">
By
defining
</ins>
a
<del class="diff-old">top-level
subject
definition
.
The
value
of
any
</del>
<ins class="diff-chg">global
language
using
the
</ins>
<code>
<del class="diff-old">@context
</del>
<ins class="diff-chg">@language
</ins>
</code>
<del class="diff-old">key
</del>
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
<ins class="diff-chg">keyword
</ins></a>
within
<del class="diff-old">that
object
is
substituted
for
</del>
<ins class="diff-chg">a
</ins><code><ins class="diff-chg">
@context
</ins></code><ins class="diff-chg">
section.
</ins></li><li><ins class="diff-chg">
By
utilizing
</ins>
the
<del class="diff-old">IRI
</del>
<code>
<ins class="diff-chg">@language
</ins></code><a class="tref internalDFN" title="keyword" href="#dfn-keyword"><ins class="diff-chg">
keyword
</ins></a><ins class="diff-chg">
when
defining
a
</ins><a class="tref internalDFN" title="term" href="#dfn-term"><ins class="diff-chg">
term
</ins></a>
within
<ins class="diff-new">a
</ins><code><ins class="diff-new">
@context
</ins></code><ins class="diff-new">
section.
</ins></li><li><ins class="diff-new">
By
utilizing
</ins>
the
<del class="diff-old">referencing
document
to
have
the
same
effect
as
if
</del>
<ins class="diff-chg">expanded
form
for
specifying
values.
</ins></li><li><ins class="diff-chg">
By
utilizing
</ins>
the
<code>
<ins class="diff-new">@container
</ins></code><a class="tref internalDFN" title="keyword" href="#dfn-keyword"><ins class="diff-new">
keyword
</ins></a><ins class="diff-new">
with
a
</ins>
value
<del class="diff-old">were
specified
inline
</del>
<ins class="diff-chg">of
</ins><code><ins class="diff-chg">
@language
</ins></code><ins class="diff-chg">
when
defining
a
</ins><a class="tref internalDFN" title="term" href="#dfn-term"><ins class="diff-chg">
term
</ins></a>
within
<del class="diff-old">the
referencing
document.
</del>
<ins class="diff-chg">a
</ins><code><ins class="diff-chg">
@context
</ins></code><ins class="diff-chg">
section.
This
usage
pattern
is
called
a
</ins><dfn title="language_map" id="dfn-language_map"><ins class="diff-chg">
language
map
</ins></dfn>.</li></ol>
<p>
The
<del class="diff-old">following
</del>
<ins class="diff-chg">first
</ins>
example
<del class="diff-old">demonstrates
</del>
<ins class="diff-chg">uses
</ins>
the
<del class="diff-old">use
of
an
external
context:
{
  ,
  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;,
  &quot;depiction&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;
}
Authors
may
also
import
multiple
contexts
or
</del>
<code>
<ins class="diff-chg">@language
</ins></code><ins class="diff-chg">
keyword
to
associate
</ins>
a
<del class="diff-old">combination
of
external
and
local
contexts
by
specifying
</del>
<ins class="diff-chg">type
with
</ins>
a
<del class="diff-old">list
of
contexts:
</del>
<ins class="diff-chg">particular
</ins><a class="tref internalDFN" title="term" href="#dfn-term"><ins class="diff-chg">
term
</ins></a><ins class="diff-chg">
in
the
</ins><code><ins class="diff-chg">
@context
</ins></code>:
</p>
<del class="diff-old">{
</del>
<div class="example"><div class="example-title"><span>Example 26</span>: Expanded term definition with language coercion</div><pre class="example">{
  <span class="diff">&quot;@context&quot;:
<del class="diff-old">  [
    &quot;http://json-ld.org/contexts/person.jsonld&quot;,
    {
      &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;
    },
    &quot;http://json-ld.org/contexts/event.jsonld&quot;
  ],
  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;,
  &quot;foaf:depiction&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;,
  &quot;celebrates&quot;:
</del>
  {
<del class="diff-old">    &quot;@type&quot;: &quot;Event&quot;,
    &quot;description&quot;: &quot;International Talk Like a Pirate Day&quot;,
    &quot;date&quot;: &quot;R/2011-09-19&quot;
  }
</del>
<ins class="diff-chg">    &quot;title&quot;:
    {
      &quot;@id&quot;: &quot;http://purl.org/dc/terms/title&quot;,
      &quot;@language&quot;: &quot;en&quot;
    }
  },</span>
...
  &quot;title&quot;: &quot;JSON-LD Syntax&quot;,
...
</ins>
}
</pre>
</div>
<p>
<del class="diff-old">Each
context
in
a
list
will
be
evaluated
in-order.
Duplicate
mappings
among
the
context
s
must
be
overwritten
on
a
last-defined-overrides
basis.
</del>
The
<del class="diff-old">context
list
must
</del>
<em>
<ins class="diff-chg">modified
</ins>
</em>
<del class="diff-old">contain
either
de-referenceable
IRI
s
or
JSON
object
s
that
conform
</del>
<ins class="diff-chg">key's
value
above
is
automatically
language
coerced
</ins>
to
<ins class="diff-new">a
English
value
because
of
</ins>
the
<del class="diff-old">context
syntax
as
described
</del>
<ins class="diff-chg">information
specified
</ins>
in
<del class="diff-old">this
document.
</del>
<ins class="diff-chg">the
</ins><code><ins class="diff-chg">
@context
</ins></code>.
</p>
<p>
<del class="diff-old">An
author
may
nest
contexts
within
subject
definitions
,
with
</del>
<ins class="diff-chg">The
second
example
uses
</ins>
the
<del class="diff-old">more
deeply
nested
contexts
overriding
</del>
<ins class="diff-chg">expanded
form
of
setting
</ins>
the
<del class="diff-old">values
</del>
<ins class="diff-chg">language
information
</ins>
in
<del class="diff-old">previously
defined
contexts:
</del>
<ins class="diff-chg">the
body
of
a
JSON-LD
document:
</ins>
</p>
<del class="diff-old">{
  &quot;@context&quot;:
  {
    &quot;name&quot;: &quot;http://example.com/person#name&quot;,
    &quot;details&quot;: &quot;http://example.com/person#details&quot;
  },
  &quot;&quot;: &quot;Markus Lanthaler&quot;,
  ...
  &quot;details&quot;:
</del>
<div class="example"><div class="example-title"><span>Example 27</span>: Expanded value with language</div><pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;:
</ins>
  {
<del class="diff-old">    &quot;@context&quot;: {
      &quot;name&quot;: &quot;http://example.com/organization#name&quot;
    },
    &quot;&quot;: &quot;Graz University of Technology&quot;
  }
</del>
<ins class="diff-chg">    &quot;title&quot;:
    {
      &quot;@id&quot;: &quot;http://purl.org/dc/terms/title&quot;
    }
  },
...
  &quot;title&quot;:
</ins>  <span class="diff">{<ins class="diff-chg">
    &quot;@value&quot;: &quot;JSON-LD Syntax&quot;,
    &quot;@language&quot;: &quot;en&quot;
  }</span>
...
</ins>
}
</pre>
</div>
<p>
<del class="diff-old">In
the
example
above,
</del>
<ins class="diff-chg">Both
examples
above
would
generate
</ins>
the
<ins class="diff-new">value
</ins>
<code>
<del class="diff-old">name
</del>
<ins class="diff-chg">JSON-LD
Syntax
</ins>
</code>
<del class="diff-old">prefix
is
overridden
in
</del>
<ins class="diff-chg">tagged
with
</ins>
the
<del class="diff-old">more
deeply
nested
</del>
<ins class="diff-chg">language
</ins>
<code>
<del class="diff-old">details
</del>
<ins class="diff-chg">en
</ins>
</code>
<del class="diff-old">structure.
Note
that
this
is
rarely
a
good
authoring
practice
and
</del>
<ins class="diff-chg">;
which
</ins>
is
<del class="diff-old">typically
used
when
</del>
the
<del class="diff-old">JSON
object
has
legacy
applications
using
the
structure
of
</del>
<ins class="diff-chg">[
</ins><cite><a class="bibref" href="#bib-BCP47"><ins class="diff-chg">
BCP47
</ins></a></cite><ins class="diff-chg">
]
code
for
</ins>
the
<del class="diff-old">object.
</del>
<ins class="diff-chg">English
language.
</ins>
</p>
<p>
<del class="diff-old">External
JSON-LD
context
documents
may
contain
extra
information
located
outside
of
the
@context
key,
</del>
<ins class="diff-chg">Systems
that
support
multiple
languages
often
need
to
express
data
values
in
each
language.
Typically,
</ins>
such
<del class="diff-old">as
documentation
about
</del>
<ins class="diff-chg">systems
also
try
to
ensure
that
developers
have
a
programatically
easy
way
to
navigate
</ins>
the
<del class="diff-old">prefixes
</del>
<ins class="diff-chg">datastructures
for
the
language-specific
data.
In
this
case,
</ins><a class="tref internalDFN" title="language_map" href="#dfn-language_map"><ins class="diff-chg">
language
map
</ins>
</a>
<del class="diff-old">declared
</del>
<ins class="diff-chg">s
may
be
utilized.
</ins></p><div class="example"><div class="example-title"><span>Example 28</span>: Language map expressing a property in three languages</div><pre class="example">{<ins class="diff-chg">
  &quot;@context&quot;:
  {
    &quot;title&quot;:
    {
      &quot;@id&quot;: &quot;http://purl.org/dc/terms/title&quot;
      &quot;@container&quot;: &quot;@language&quot;
    }
  },
...
  &quot;title&quot;:
</ins>  <span class="diff">{<ins class="diff-chg">
    &quot;en&quot;: &quot;JSON-LD Syntax&quot;,
    &quot;ru&quot;: &quot;JSON-LD Синтаксис&quot;,
    &quot;ja&quot;: &quot;JSON-LDの構文&quot;
  }</span>
...
}
</ins></pre></div><p><ins class="diff-chg">
In
the
example
above,
the
title
is
expressed
</ins>
in
<ins class="diff-new">three
languages;
English,
Russian,
and
Japanese.
To
access
</ins>
the
<del class="diff-old">document.
When
importing
</del>
<ins class="diff-chg">data
above
in
</ins>
a
<del class="diff-old">@context
value
from
an
external
JSON-LD
context
document,
any
extra
information
contained
outside
of
</del>
<ins class="diff-chg">programming
language
supporting
dot-notation
accessors
for
object
properties,
a
developer
may
use
</ins>
the
<code>
<del class="diff-old">@context
</del>
<ins class="diff-chg">property.language
</ins>
</code>
<del class="diff-old">value
must
be
discarded.
It
is
also
recommended
that
a
human-readable
document
is
served
as
well
</del>
<ins class="diff-chg">pattern.
For
example,
</ins>
to
<del class="diff-old">explain
</del>
<ins class="diff-chg">access
</ins>
the
<del class="diff-old">correct
usage
</del>
<ins class="diff-chg">Japanese
version
</ins>
of
the
<del class="diff-old">JSON-LD
context
document.
</del>
<ins class="diff-chg">title,
a
developer
would
use
the
following
code
snippet:
</ins><code><ins class="diff-chg">
obj.title.ja
</ins></code>.
</p>
</section>
<section id="referencing-contexts-from-json-documents">
<h3>
<span class="secno">
4.4
</span>
Referencing
Contexts
from
JSON
Documents
</h3>
<p>
Ordinary
JSON
documents
can
be
transformed
into
JSON-LD
documents
by
referencing
to
an
external
JSON-LD
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>
in
an
HTTP
Link
Header.
Doing
this
allows
JSON
to
be
unambiguously
machine-readable
without
requiring
developers
to
drastically
change
their
workflow
and
provides
an
upgrade
path
for
existing
infrastructure
without
breaking
existing
clients
that
rely
on
the
<code>
application/json
</code>
media
type.
</p>
<p>
In
order
to
use
an
external
context
with
an
ordinary
JSON
document,
an
author
<em class="rfc2119" title="must">
must
</em>
specify
an
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
to
a
valid
JSON-LD
document
in
an
HTTP
Link
Header
[
<cite>
<a class="bibref" href="#bib-RFC5988">
RFC5988
</a>
</cite>
]
using
the
<code>
describedby
</code>
link
relation.
The
referenced
document
<em class="rfc2119" title="must">
must
</em>
have
a
top-level
<del class="diff-old">subject
</del>
<a class="tref internalDFN" title="node_definition" href="#dfn-node_definition">
<ins class="diff-chg">node
</ins>
definition
</a>.
The
<code>
@context
</code>
subtree
within
that
object
is
added
to
the
top-level
<del class="diff-old">subject
</del>
<a class="tref internalDFN" title="node_definition" href="#dfn-node_definition">
<ins class="diff-chg">node
</ins>
definition
</a>
of
the
referencing
document.
If
an
<a class="tref internalDFN" title="array" href="#dfn-array">
array
</a>
is
at
the
top-level
of
the
referencing
document
and
its
items
are
<del class="diff-old">subject
</del>
<a class="tref internalDFN" title="node_definition" href="#dfn-node_definition">
<ins class="diff-chg">node
</ins>
definitions
</a>,
the
<code>
@context
</code>
subtree
is
added
to
all
<a class="tref internalDFN" title="array" href="#dfn-array">
array
</a>
items.
All
extra
information
located
outside
of
the
<code>
@context
</code>
subtree
in
the
referenced
document
<em class="rfc2119" title="must">
must
</em>
be
discarded.
</p>
<p>
The
following
example
demonstrates
the
use
of
an
external
context
with
an
ordinary
JSON
document:
</p>
<del class="diff-old">GET /ordinary-json-document.json HTTP/1.1
</del>
<div class="example"><div class="example-title"><span>Example 29</span>: Specifing context through HTTP header</div><pre class="example">GET /ordinary-json-document.json HTTP/1.1
Host: example.com
Accept: application/ld+json,application/json,*/*;q=0.1
====================================
HTTP/1.0 200 OK
...
Content-Type: <span class="diff">application/json</span>
<span class="diff">Link: &lt;http://json-ld.org/contexts/person.jsonld&gt;; rel=&quot;describedby&quot;; type=&quot;application/ld+json&quot;</span>
{
  &quot;name&quot;: &quot;Markus Lanthaler&quot;,
  &quot;homepage&quot;: &quot;http://www.markus-lanthaler.com/&quot;,
  &quot;depiction&quot;: &quot;http://twitter.com/account/profile_image/markuslanthaler&quot;
}
</pre>
</div>
<div class="note">
<div class="note-title">
<span>
Note
</span>
</div>
<p class="">
JSON-LD
documents
served
with
the
<code>
application/ld+json
</code>
media
type
<em class="rfc2119" title="must">
must
</em>
have
all
context
information,
including
references
to
external
contexts,
within
the
body
of
the
document.
</p>
</div>
</section>
<section id="expanded-term-definition">
<h3>
<span class="secno">
4.5
</span>
Expanded
Term
Definition
</h3>
<p>
Within
a
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>
definition,
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
s
<em class="rfc2119" title="may">
may
</em>
be
defined
using
an
expanded
notation
to
allow
for
additional
information
associated
with
the
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
to
be
specified
(see
also
<a href="#type-coercion" class="sec-ref">
<span class="secno">
<ins class="diff-chg">4.6
</ins></span><span class="sec-title">
Type
Coercion
</span>
</a>
and
<a href="#sets-and-lists" class="sec-ref">
<span class="secno">
<ins class="diff-chg">4.9
</ins></span><span class="sec-title">
Sets
and
Lists
</span>
</a>
).
</p>
<p>
Instead
of
using
a
string
representation
of
an
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>,
the
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
<em class="rfc2119" title="may">
may
</em>
be
specified
using
a
<a class="tref internalDFN" title="json_object" href="#dfn-json_object">
JSON
object
</a>
having
an
<code>
@id
</code>
key.
The
value
of
the
<code>
@id
</code>
key
<em class="rfc2119" title="must">
must
</em>
be
either
a
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>,
a
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
compact
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>,
or
an
<a class="tref internalDFN" title="absolute_iri" href="#dfn-absolute_iri">
absolute
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>.
Such
an
object
is
called
a
<del class="diff-old">subject
</del>
<a class="tref internalDFN" title="node_reference" href="#dfn-node_reference">
<ins class="diff-chg">node
</ins>
reference
</a>.
</p>
<del class="diff-old">{
</del>
<div class="example"><div class="example-title"><span>Example 30</span>: Expanded term definition</div><pre class="example">{
  &quot;@context&quot;:
  {
    &quot;foaf&quot;: <span class="diff">{ &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/&quot; }</span>,
    &quot;name&quot;: <span class="diff">{ &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/name&quot; }</span>,
    &quot;homepage&quot;: <span class="diff">{ &quot;@id&quot;: &quot;foaf:homepage&quot; }</span>,
    &quot;depiction&quot;: <span class="diff">{ &quot;@id&quot;: &quot;foaf:depiction&quot; }</span>
  },
  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;,
  &quot;depiction&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;
}
</pre>
</div>
<p>
This
allows
additional
information
to
be
associated
with
the
term.
This
<em class="rfc2119" title="may">
may
</em>
be
used
for
<a href="#type-coercion" class="sec-ref">
<span class="secno">
<ins class="diff-chg">4.6
</ins></span><span class="sec-title">
Type
Coercion
</span>
</a>,
<a href="#sets-and-lists" class="sec-ref">
<span class="secno">
<ins class="diff-chg">4.9
</ins></span><span class="sec-title">
Sets
and
Lists
</span>
</a>
),
or
to
associate
language
information
with
a
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
as
shown
in
the
following
example:
</p>
<del class="diff-old">{
</del>
<div class="example"><div class="example-title"><span>Example 31</span>: Expanded term definition with language</div><pre class="example">{
  &quot;@context&quot;: {
    ...
    &quot;ex&quot;: &quot;http://example.com/&quot;,
    &quot;@language&quot;: &quot;ja&quot;,
    &quot;name&quot;: { &quot;@id&quot;: &quot;ex:name&quot;, <span class="diff">&quot;@language&quot;: null</span> },
    &quot;occupation&quot;: { &quot;@id&quot;: &quot;ex:occupation&quot; },
    &quot;occupation_en&quot;: { &quot;@id&quot;: &quot;ex:occupation&quot;, <span class="diff">&quot;@language&quot;: &quot;en&quot;</span> },
    &quot;occupation_cs&quot;: { &quot;@id&quot;: &quot;ex:occupation&quot;, <span class="diff">&quot;@language&quot;: &quot;cs&quot;</span> }
  },
  <span class="diff">&quot;name&quot;: &quot;Yagyū Muneyoshi&quot;,
  &quot;occupation&quot;: &quot;忍者&quot;,
  &quot;occupation_en&quot;: &quot;Ninja&quot;,
  &quot;occupation_cs&quot;: &quot;Nindža&quot;,</span>
  ...
}
</pre>
</div>
<p>
The
example
above
would
associate
<em>
忍者
</em>
with
the
specified
default
language
code
<code>
ja
</code>,
<em>
Ninja
</em>
with
the
language
code
<code>
en
</code>,
and
<em>
Nindža
</em>
with
the
language
code
<code>
cs
</code>.
The
value
of
<code>
name
</code>,
<em>
Yagyū
Muneyoshi
</em>
wouldn't
be
associated
with
any
language
code
since
<code>
@language
</code>
was
reset
to
<a class="tref internalDFN" title="null" href="#dfn-null">
null
</a>
in
the
expanded
term
definition.
</p>
<p>
Expanded
terms
<em class="rfc2119" title="may">
may
</em>
also
be
defined
using
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
compact
IRIs
</a>
or
<a class="tref internalDFN" title="absolute_iri" href="#dfn-absolute_iri">
absolute
IRIs
</a>
as
keys.
If
the
definition
does
not
include
an
<code>
@id
</code>
key,
the
expanded
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
is
determined
by
performing
expansion
of
the
key
within
the
current
active
context.
This
mechanism
is
mainly
used
to
associate
type
or
language
information
with
a
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
compact
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
or
an
<a class="tref internalDFN" title="absolute_iri" href="#dfn-absolute_iri">
absolute
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>.
</p>
<div class="note">
<div class="note-title">
<span>
Note
</span>
</div>
<p class="">
While
it
is
possible
to
define
a
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
compact
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>,
or
an
absolute
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
to
expand
to
some
other
unrelated
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
(for
example,
<code>
foaf:name
</code>
expanding
to
<code>
http://example.org/unrelated#species
</code>
),
such
usage
is
strongly
discouraged.
</p>
</div>
</section>
<section id="type-coercion">
<h3>
<span class="secno">
4.6
</span>
Type
Coercion
</h3>
<p>
JSON-LD
supports
the
coercion
of
values
to
particular
data
types.
Type
<dfn title="coercion" id="dfn-coercion">
coercion
</dfn>
allows
someone
deploying
JSON-LD
to
coerce
the
incoming
or
outgoing
values
to
the
proper
data
type
based
on
a
mapping
of
data
type
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
s
to
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
s.
Using
type
coercion,
value
representation
is
preserved
without
requiring
the
data
type
to
be
specified
with
each
piece
of
data.
</p>
<p>
Type
coercion
is
specified
within
an
<del class="diff-old">expanded
term
definition
</del>
<a href="#expanded-term-definition" class="sec-ref">
<span class="secno">
<ins class="diff-chg">4.5
</ins></span><span class="sec-title"><ins class="diff-chg">
Expanded
Term
Definition
</ins></span>
</a>
using
the
<code>
@type
</code>
key.
The
value
of
this
key
represents
a
type
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
and
<em class="rfc2119" title="must">
must
</em>
take
the
form
of
a
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>,
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
compact
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>,
<a class="tref internalDFN" title="absolute_iri" href="#dfn-absolute_iri">
absolute
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>,
or
the
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
keyword
</a>
<code>
@id
</code>.
Specifying
<code>
@id
</code>
indicates
that
within
the
body
of
a
JSON-LD
document,
a
string
value
of
a
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
coerced
to
<code>
@id
</code>
is
to
be
interpreted
as
an
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>.
</p>
<p>
<a class="tref internalDFN" title="term" href="#dfn-term">
Terms
</a>
or
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
compact
IRIs
</a>
used
as
the
value
of
a
<code>
@type
</code>
key
<em class="rfc2119" title="may">
may
</em>
be
defined
within
the
same
context.
This
means
that
one
may
specify
a
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
like
<code>
xsd
</code>
and
then
use
<code>
xsd:integer
</code>
within
the
same
context
definition
-
the
JSON-LD
processor
will
be
able
to
determine
the
proper
expansion
for
<code>
xsd:integer
</code>.
</p>
<p>
The
example
below
demonstrates
how
a
JSON-LD
author
can
coerce
values
to
<a class="tref internalDFN" title="typed_value" href="#dfn-typed_value">
typed
value
</a>
s,
IRIs
and
lists.
</p>
<del class="diff-old">{
</del>
<div class="example"><div class="example-title"><span>Example 32</span>: Expanded term definition with types</div><pre class="example">{
  &quot;@context&quot;:
  {
    &quot;xsd&quot;: &quot;http://www.w3.org/2001/XMLSchema#&quot;,
    &quot;name&quot;: &quot;http://xmlns.com/foaf/0.1/name&quot;,
    &quot;age&quot;:
    <span class="diff">{
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/age&quot;,
      &quot;@type&quot;: &quot;xsd:integer&quot;
    }</span>,
    &quot;homepage&quot;:
    <span class="diff">{
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/homepage&quot;,
      &quot;@type&quot;: &quot;@id&quot;,
      &quot;@container&quot;: &quot;@list&quot;
    }</span>
  },
  &quot;name&quot;: &quot;John Smith&quot;,
  &quot;age&quot;: <span class="diff">&quot;41&quot;</span>,
  &quot;homepage&quot;:
  <span class="diff">[
    &quot;http://personal.example.org/&quot;,
    &quot;http://work.example.com/jsmith/&quot;
  ]</span>
}
</pre>
</div>
<p>
The
example
above
would
generate
the
following
Turtle:
</p>
<del class="diff-old">@prefix xsd: &lt;http://www.w3.org/2001/XMLSchema#&gt; .
</del>
<div class="example"><div class="example-title"><span>Example 33</span></div><pre class="example">@prefix xsd: &lt;http://www.w3.org/2001/XMLSchema#&gt; .
[ foaf:name &quot;John Smith&quot;;
  foaf:age  &quot;41&quot;^^xsd:integer;
  foaf:homepage ( &lt;http://personal.example.org/&gt; &lt;http://work.example.com/jsmith/&gt; )
]
.
</pre>
</div>
<p>
Terms
may
also
be
defined
using
<a class="tref internalDFN" title="absolute_iri" href="#dfn-absolute_iri">
absolute
IRIs
</a>
or
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
compact
IRIs
</a>.
This
allows
coercion
rules
to
be
applied
to
keys
which
are
not
represented
as
a
simple
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>.
For
example:
</p>
<del class="diff-old">{
</del>
<div class="example"><div class="example-title"><span>Example 34</span>: Term definition with absolute IRI</div><pre class="example">{
  &quot;@context&quot;:
  {
    <span class="diff">&quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;</span>,
    &quot;<span class="diff">foaf:age</span>&quot;:
    {
      &quot;@type&quot;: &quot;xsd:integer&quot;
    },
    &quot;<span class="diff">foaf:homepage</span>&quot;:
    <span class="diff">{
      &quot;@type&quot;: &quot;@id&quot;
    }</span>
  },
  &quot;foaf:name&quot;: &quot;John Smith&quot;,
  &quot;foaf:age&quot;: <span class="diff">&quot;41&quot;</span>,
  &quot;foaf:homepage&quot;:
  <span class="diff">[
    &quot;http://personal.example.org/&quot;,
    &quot;http://work.example.com/jsmith/&quot;
  ]</span>
}
</pre>
</div>
<p>
In
this
case
the
<code>
@id
</code>
definition
is
optional,
but
if
it
does
exist,
the
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
compact
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
or
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
is
treated
as
a
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
(not
a
<code>
prefix:suffix
</code>
construct)
so
that
the
actual
definition
of
a
<a class="tref internalDFN" title="prefix" href="#dfn-prefix">
prefix
</a>
becomes
unnecessary.
</p>
<div class="note">
<div class="note-title">
<span>
Note
</span>
</div>
<p class="">
Keys
in
the
context
are
treated
as
<a class="tref internalDFN" title="term" href="#dfn-term">
terms
</a>
for
the
purpose
of
expansion
and
value
coercion.
At
times,
this
may
result
in
multiple
representations
for
the
same
expanded
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>.
For
example,
one
could
specify
that
<code>
dog
</code>
and
<code>
cat
</code>
both
expanded
to
<code>
http://example.com/vocab#animal
</code>.
Doing
this
could
be
useful
for
establishing
different
type
coercion
or
language
specification
rules.
It
also
allows
a
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
compact
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
(or
even
an
absolute
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
)
to
be
defined
as
something
else
entirely.
For
example,
one
could
specify
that
the
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
<code>
http://example.org/zoo
</code>
should
expand
to
<code>
http://example.org/river
</code>,
but
this
usage
is
discouraged
because
it
would
lead
to
a
great
deal
of
confusion
among
developers
attempting
to
understand
the
JSON-LD
document.
</p>
</div>
<p>
Type
coercion
is
performed
using
the
unexpanded
value
of
the
key,
which
<em class="rfc2119" title="must">
must
</em>
have
an
exact
match
for
an
entry
in
the
<a class="tref internalDFN" title="active_context" href="#dfn-active_context">
active
context
</a>.
</p>
</section>
<section id="property-generators">
<h3>
<span class="secno">
4.7
</span>
<ins class="diff-new">Property
Generators
</ins></h3><p><ins class="diff-new">
At
times,
an
author
may
find
that
they
need
to
express
the
same
value
for
multiple
properties.
The
simplest
approach
to
accomplish
this
goal
would
be
to
do
the
following:
</ins></p><div class="example"><div class="example-title"><span>Example 35</span>: Verbose expression of multiple properties with the same value</div><pre class="example">{<ins class="diff-new">
  &quot;@context&quot;:
  {
</ins>    <span class="diff">&quot;title1&quot;: &quot;http://purl.org/dc/terms/title&quot;</span>,    <span class="diff">&quot;title2&quot;: &quot;http://schema.org/name&quot;</span>,    <span class="diff">&quot;title3&quot;: &quot;http://www.w3.org/2000/01/rdf-schema#label&quot;</span><ins class="diff-new">
  },
  &quot;@id&quot;: &quot;http://example.com/book&quot;,
</ins>  <span class="diff">&quot;title1&quot;: &quot;The Count of Monte Cristo&quot;</span>,  <span class="diff">&quot;title2&quot;: &quot;The Count of Monte Cristo&quot;</span>,  <span class="diff">&quot;title3&quot;: &quot;The Count of Monte Cristo&quot;</span><ins class="diff-new">
}
</ins></pre></div><p><ins class="diff-new">
Unfortunately,
the
approach
above
produces
redundant
data
and
would
become
a
publishing
burden
for
large
data
sets.
In
these
situations,
the
author
may
use
a
</ins><dfn title="property_generator" id="dfn-property_generator"><ins class="diff-new">
property
generator
</ins></dfn><ins class="diff-new">
to
express
a
</ins><a class="tref internalDFN" title="term" href="#dfn-term"><ins class="diff-new">
term
</ins></a><ins class="diff-new">
once,
but
have
the
JSON-LD
processor
expand
the
single
statement
into
multiple
statements.
This
method
can
be
accomplished
by
using
the
following
markup
pattern:
</ins></p><div class="example"><div class="example-title"><span>Example 36</span>: Generating multiple properties using a single term</div><pre class="example">{<ins class="diff-new">
  &quot;@context&quot;:
  {
</ins>    <span class="diff">&quot;title&quot;: { &quot;@id&quot;: [ &quot;http://purl.org/dc/terms/title&quot;,<ins class="diff-new">
                        &quot;http://schema.org/name&quot;,
                        &quot;http://www.w3.org/2000/01/rdf-schema#label&quot; ] }</span>
  },
  &quot;@id&quot;: &quot;http://example.com/book&quot;,
</ins>  <span class="diff">&quot;title&quot;: &quot;The Count of Monte Cristo&quot;</span><ins class="diff-new">
}
</ins></pre></div><p><ins class="diff-new">
While
the
term
above
is
only
used
once
outside
of
the
</ins><code><ins class="diff-new">
@context
</ins></code>,<ins class="diff-new">
a
JSON-LD
processor
will
internally
transform
the
document
above
into
the
following
set
of
statements:
</ins></p><div class="example"><div class="example-title"><span>Example 37</span></div><pre class="example">&lt;http://example.com/book&gt;<ins class="diff-new">
  &lt;http://purl.org/dc/terms/title&gt;
    &quot;The Count of Monte Cristo&quot; .
&lt;http://example.com/book&gt;
  &lt;http://schema.org/name&gt;
    &quot;The Count of Monte Cristo&quot; .
&lt;http://example.com/book&gt;
  &lt;http://www.w3.org/2000/01/rdf-schema#label&gt;
&quot;The
Count
of
Monte
Cristo&quot;
.
</ins></pre></div></section><section id="iri-expansion-within-a-context"><h3><span class="secno"><ins class="diff-new">
4.8
</ins></span>
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
Expansion
Within
a
Context
</h3>
<p>
In
general,
normal
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
expansion
rules
apply
anywhere
an
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
is
expected
(see
<a href="#iris" class="sec-ref">
<span class="secno">
<ins class="diff-chg">3.7
</ins></span><span class="sec-title">
IRIs
</span>
</a>
).
Within
a
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>
definition,
this
can
mean
that
terms
defined
within
the
context
<em class="rfc2119" title="may">
may
</em>
also
be
used
within
that
context
as
long
as
there
are
no
circular
dependencies.
For
example,
it
is
common
to
use
the
<code>
xsd
</code>
namespace
when
defining
<a class="tref internalDFN" title="typed_value" href="#dfn-typed_value">
typed
value
</a>
s:
</p>
<del class="diff-old">{
</del>
<div class="example"><div class="example-title"><span>Example 38</span>: IRI expansion within context</div><pre class="example">{
  &quot;@context&quot;:
  {
    <span class="diff">&quot;xsd&quot;: &quot;http://www.w3.org/2001/XMLSchema#&quot;</span>,
    &quot;name&quot;: &quot;http://xmlns.com/foaf/0.1/name&quot;,
    &quot;age&quot;:
    {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/age&quot;,
      &quot;@type&quot;: <span class="diff">&quot;xsd:integer&quot;</span>
    },
    &quot;homepage&quot;:
    {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/homepage&quot;,
      &quot;@type&quot;: &quot;@id&quot;
    }
  },
  ...
}
</pre>
</div>
<p>
In
this
example,
the
<code>
xsd
</code>
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
is
defined
and
used
as
a
<a class="tref internalDFN" title="prefix" href="#dfn-prefix">
prefix
</a>
for
the
<code>
@type
</code>
coercion
of
the
<code>
age
</code>
property.
</p>
<p>
<a class="tref internalDFN" title="term" href="#dfn-term">
Term
</a>
s
<em class="rfc2119" title="may">
may
</em>
also
be
used
when
defining
the
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
of
another
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>:
</p>
<del class="diff-old">{
</del>
<div class="example"><div class="example-title"><span>Example 39</span></div><pre class="example">{
  &quot;@context&quot;:
  {
    <span class="diff">&quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;</span>,
    &quot;xsd&quot;: &quot;http://www.w3.org/2001/XMLSchema#&quot;,
    &quot;name&quot;: <span class="diff">&quot;foaf:name&quot;</span>,
    &quot;age&quot;:
    {
      &quot;@id&quot;: <span class="diff">&quot;foaf:age&quot;</span>,
      &quot;@type&quot;: &quot;xsd:integer&quot;
    },
    &quot;homepage&quot;:
    {
      &quot;@id&quot;: <span class="diff">&quot;foaf:homepage&quot;</span>,
      &quot;@type&quot;: &quot;@id&quot;
    }
  },
  ...
}
</pre>
</div>
<p>
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
Compact
IRIs
</a>
and
<a class="tref internalDFN" title="iri" href="#dfn-iri">
IRIs
</a>
<em class="rfc2119" title="may">
may
</em>
be
used
on
the
left-hand
side
of
a
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
definition.
</p>
<del class="diff-old">{
</del>
<div class="example"><div class="example-title"><span>Example 40</span></div><pre class="example">{
  &quot;@context&quot;:
  {
    <span class="diff">&quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;</span>,
    &quot;xsd&quot;: &quot;http://www.w3.org/2001/XMLSchema#&quot;,
    &quot;name&quot;: &quot;foaf:name&quot;,
    &quot;<span class="diff">foaf:age</span>&quot;:
    {
      &quot;@type&quot;: &quot;xsd:integer&quot;
    },
    &quot;<span class="diff">foaf:homepage</span>&quot;:
    <span class="diff">{
      &quot;@type&quot;: &quot;@id&quot;
    }</span>
  },
  ...
}
</pre>
</div>
<p>
In
this
example,
the
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
compact
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
form
is
used
in
two
different
ways.
In
the
first
approach,
<code>
foaf:age
</code>
declares
both
the
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
for
the
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
(using
short-form)
as
well
as
the
<code>
@type
</code>
associated
with
the
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>.
In
the
second
approach,
only
the
<code>
@type
</code>
associated
with
the
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
is
specified.
The
JSON-LD
processor
will
derive
the
full
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
for
<code>
foaf:homepage
</code>
by
looking
up
the
<code>
foaf
</code>
<a class="tref internalDFN" title="prefix" href="#dfn-prefix">
prefix
</a>
in
the
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>.
</p>
<p>
<a class="tref internalDFN" title="absolute_iri" href="#dfn-absolute_iri">
Absolute
IRIs
</a>
<em class="rfc2119" title="may">
may
</em>
also
be
used
in
the
key
position
in
a
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>:
</p>
<del class="diff-old">{
</del>
<div class="example"><div class="example-title"><span>Example 41</span></div><pre class="example">{
  &quot;@context&quot;:
  {
    &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;,
    &quot;xsd&quot;: &quot;http://www.w3.org/2001/XMLSchema#&quot;,
    &quot;name&quot;: &quot;foaf:name&quot;,
    &quot;foaf:age&quot;:
    {
      &quot;@id&quot;: &quot;foaf:age&quot;,
      &quot;@type&quot;: &quot;xsd:integer&quot;
    },
    &quot;<span class="diff">http://xmlns.com/foaf/0.1/homepage</span>&quot;:
    {
      &quot;@type&quot;: &quot;@id&quot;
    }
  },
  ...
}
</pre>
</div>
<p>
In
order
for
the
<a class="tref internalDFN" title="absolute_iri" href="#dfn-absolute_iri">
absolute
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
to
match
above,
the
<a class="tref internalDFN" title="absolute_iri" href="#dfn-absolute_iri">
absolute
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
<em class="rfc2119" title="must">
must
</em>
also
be
used
in
the
JSON-LD
document.
Also
note
that
<code>
foaf:homepage
</code>
will
not
use
the
<code>
{
&quot;@type&quot;:
&quot;@id&quot;
}
</code>
declaration
because
<code>
foaf:homepage
</code>
is
not
the
same
as
<code>
http://xmlns.com/foaf/0.1/homepage
</code>.
That
is,
a
JSON-LD
processor
will
use
direct
string
comparison
when
looking
up
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
s
in
a
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>
before
it
applies
the
<a class="tref internalDFN" title="prefix" href="#dfn-prefix">
prefix
</a>
lookup
mechanism.
</p>
<p>
The
only
exception
for
using
terms
in
the
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>
is
that
they
<em class="rfc2119" title="must not">
must
not
</em>
be
used
in
a
circular
manner.
That
is,
a
definition
of
<em>
term-1
</em>
<em class="rfc2119" title="must not">
must
not
</em>
depend
on
the
definition
of
<em>
term-2
</em>
if
<em>
term-2
</em>
also
depends
on
<em>
term-1
</em>.
For
example,
the
following
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>
definition
is
illegal:
</p>
<del class="diff-old">{
</del>
<div class="example"><div class="example-title"><span>Example 42</span></div><pre class="example">{
  &quot;@context&quot;:
  {
    <span class="diff">&quot;term1&quot;: &quot;term2:foo&quot;,
    &quot;term2&quot;: &quot;term1:bar&quot;</span>
  },
  ...
}
</pre>
</div>
</section>
<section id="sets-and-lists">
<h3>
<span class="secno">
<del class="diff-old">4.8
</del>
<ins class="diff-chg">4.9
</ins>
</span>
Sets
and
Lists
</h3>
<p>
A
JSON-LD
author
can
express
multiple
values
in
a
compact
way
by
using
<a class="tref internalDFN" title="array" href="#dfn-array">
array
</a>
s.
Since
graphs
do
not
describe
ordering
for
links
between
nodes,
arrays
in
JSON-LD
do
not
provide
an
ordering
of
the
<del class="diff-old">listed
objects
</del>
<ins class="diff-chg">contained
elements
</ins>
by
default.
This
is
exactly
the
opposite
from
regular
JSON
arrays,
which
are
ordered
by
default.
For
example,
consider
the
following
simple
document:
</p>
<del class="diff-old">{
</del>
<div class="example"><div class="example-title"><span>Example 43</span></div><pre class="example">{
...
  &quot;@id&quot;: &quot;http://example.org/people#joebob&quot;,
  &quot;nick&quot;: <span class="diff">[ &quot;joe&quot;, &quot;bob&quot;, &quot;jaybee&quot; ]</span>,
...
}
</pre>
</div>
<p>
The
markup
shown
above
would
result
in
<del class="diff-old">three
triples
</del>
<ins class="diff-chg">the
following
data
</ins>
being
generated,
each
relating
the
<del class="diff-old">subject
</del>
<ins class="diff-chg">node
</ins>
to
an
individual
<del class="diff-old">object
,
</del>
<ins class="diff-chg">value,
</ins>
with
no
inherent
order:
</p>
<del class="diff-old">&lt;http://example.org/people#joebob&gt;
   &lt;http://xmlns.com/foaf/0.1/nick&gt;
      &quot;joe&quot; .
&lt;http://example.org/people#joebob&gt;
   &lt;http://xmlns.com/foaf/0.1/nick&gt;
      &quot;bob&quot; .
&lt;http://example.org/people#joebob&gt;
   &lt;http://xmlns.com/foaf/0.1/nick&gt;
&quot;jaybee&quot;
.
</del>
<table class="example">
<thead>
<tr>
<th>
<ins class="diff-chg">Subject
</ins></th><th><ins class="diff-chg">
Property
</ins></th><th><ins class="diff-chg">
Object
</ins></th></tr></thead><tbody><tr><td><ins class="diff-chg">
http://example.org/people#joebob
</ins></td><td><ins class="diff-chg">
http://xmlns.com/foaf/0.1/nick
</ins></td><td><ins class="diff-chg">
joe
</ins></td></tr><tr><td><ins class="diff-chg">
http://example.org/people#joebob
</ins></td><td><ins class="diff-chg">
http://xmlns.com/foaf/0.1/nick
</ins></td><td><ins class="diff-chg">
bob
</ins></td></tr><tr><td><ins class="diff-chg">
http://example.org/people#joebob
</ins></td><td><ins class="diff-chg">
http://xmlns.com/foaf/0.1/nick
</ins></td><td><ins class="diff-chg">
jaybee
</ins></td></tr></tbody></table>
<p>
Multiple
values
may
also
be
expressed
using
the
expanded
form:
</p>
<del class="diff-old">{
</del>
<div class="example"><div class="example-title"><span>Example 44</span></div><pre class="example">{
  &quot;@id&quot;: &quot;http://example.org/articles/8&quot;,
  &quot;dc:title&quot;: <span class="diff">
  [
    {
      &quot;@value&quot;: &quot;Das Kapital&quot;,
      &quot;@language&quot;: &quot;de&quot;
    },
    {
      &quot;@value&quot;: &quot;Capital&quot;,
      &quot;@language&quot;: &quot;en&quot;
    }
  ]</span>
}
</pre>
</div>
<p>
The
markup
shown
above
would
generate
the
following
<del class="diff-old">triples,
</del>
<ins class="diff-chg">data,
</ins>
again
with
no
inherent
order:
</p>
<del class="diff-old">&lt;http://example.org/articles/8&gt;
   &lt;http://purl.org/dc/terms/title&gt;
      &quot;Das Kapital&quot;@de .
&lt;http://example.org/articles/8&gt;
   &lt;http://purl.org/dc/terms/title&gt;
&quot;Capital&quot;@en
.
</del>
<table class="example">
<thead>
<tr>
<th>
<ins class="diff-chg">Subject
</ins></th><th><ins class="diff-chg">
Property
</ins></th><th><ins class="diff-chg">
Object
</ins></th><th><ins class="diff-chg">
Language
</ins></th></tr></thead><tbody><tr><td><ins class="diff-chg">
http://example.org/articles/8
</ins></td><td><ins class="diff-chg">
http://purl.org/dc/terms/title
</ins></td><td><ins class="diff-chg">
Das
Kapital
</ins></td><td><ins class="diff-chg">
de
</ins></td></tr><tr><td><ins class="diff-chg">
http://example.org/articles/8
</ins></td><td><ins class="diff-chg">
http://purl.org/dc/terms/title
</ins></td><td><ins class="diff-chg">
Capital
</ins></td><td><ins class="diff-chg">
en
</ins></td></tr></tbody></table>
<p>
As
the
notion
of
ordered
collections
is
rather
important
in
data
modeling,
it
is
useful
to
have
specific
language
support.
In
JSON-LD,
a
list
may
be
represented
using
the
<code>
@list
</code>
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
keyword
</a>
as
follows:
</p>
<del class="diff-old">{
</del>
<div class="example"><div class="example-title"><span>Example 45</span></div><pre class="example">{
...
  &quot;@id&quot;: &quot;http://example.org/people#joebob&quot;,
  &quot;foaf:nick&quot;:
  <span class="diff">{
    &quot;@list&quot;: [ &quot;joe&quot;, &quot;bob&quot;, &quot;jaybee&quot; ]
  }</span>,
...
}
</pre>
</div>
<p>
This
describes
the
use
of
this
<a class="tref internalDFN" title="array" href="#dfn-array">
array
</a>
as
being
ordered,
and
order
is
maintained
when
processing
a
document.
If
every
use
of
a
given
multi-valued
property
is
a
list,
this
may
be
abbreviated
by
setting
<code>
@container
</code>
to
<code>
@list
</code>
in
the
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>:
</p>
<del class="diff-old">{
</del>
<div class="example"><div class="example-title"><span>Example 46</span></div><pre class="example">{
  <span class="diff">&quot;@context&quot;:
  {
    ...
    &quot;nick&quot;:
    {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/nick&quot;,
      &quot;@container&quot;: &quot;@list&quot;
    }
  }</span>,
...
  &quot;@id&quot;: &quot;http://example.org/people#joebob&quot;,
  &quot;nick&quot;: <span class="diff">[ &quot;joe&quot;, &quot;bob&quot;, &quot;jaybee&quot; ]</span>,
...
}
</pre>
</div>
<div class="note">
<div class="note-title">
<span>
Note
</span>
</div>
<p class="">
List
of
lists
are
not
allowed
in
this
version
of
JSON-LD.
If
a
list
of
lists
is
detected,
a
JSON-LD
processor
will
throw
an
exception.
This
decision
was
made
due
to
the
extreme
amount
of
added
complexity
when
processing
lists
of
lists.
</p>
</div>
<p>
Similarly
to
<code>
@list
</code>,
there
exists
the
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
keyword
</a>
<code>
@set
</code>
to
describe
unordered
sets.
While
its
use
in
the
body
of
a
JSON-LD
document
represents
just
syntactic
sugar
that
<em class="rfc2119" title="must">
must
</em>
be
optimized
away
when
processing
the
document,
it
is
very
helpful
when
used
within
the
context
of
a
document.
Values
of
terms
associated
with
a
<code>
@set
</code>
or
<code>
@list
</code>
container
are
always
represented
in
the
form
of
an
<a class="tref internalDFN" title="array" href="#dfn-array">
array
</a>
-
even
if
there
is
just
a
single
value
that
would
otherwise
be
optimized
to
a
non-array
form
in
a
<del class="diff-old">compacted
document
</del>
<a href="#compact-document-form" class="sec-ref">
<span class="secno">
<ins class="diff-chg">4.15
</ins></span><span class="sec-title"><ins class="diff-chg">
Compact
Document
Form
</ins></span>
</a>.
This
makes
post-processing
of
the
data
easier
as
the
data
is
always
in
array
form,
even
if
the
array
only
contains
a
single
value.
</p>
<div class="note">
<div class="note-title">
<span>
Note
</span>
</div>
<p class="">
The
use
of
<code>
@container
</code>
in
the
body
of
a
JSON-LD
document,
i.e.,
outside
<code>
@context
</code>
<em class="rfc2119" title="must">
must
</em>
be
ignored
by
JSON-LD
processors.
</p>
</div>
</section>
<section id="embedding">
<h3>
<span class="secno">
<del class="diff-old">4.9
</del>
<ins class="diff-chg">4.10
</ins>
</span>
Embedding
</h3>
<p>
<del class="diff-old">Object
</del>
<dfn title="embedding" id="dfn-embedding">
<del class="diff-old">embedding
</del>
<ins class="diff-chg">Embedding
</ins>
</dfn>
is
a
JSON-LD
feature
that
allows
an
author
to
use
<del class="diff-old">subject
</del>
<a class="tref internalDFN" title="node_definition" href="#dfn-node_definition">
<ins class="diff-chg">node
</ins>
definitions
</a>
as
<a class="tref internalDFN" title="property" href="#dfn-property">
property
</a>
values.
This
is
a
commonly
used
mechanism
for
creating
a
parent-child
relationship
between
two
<del class="diff-old">subject
</del>
<a class="tref internalDFN" title="node" href="#dfn-node">
<ins class="diff-chg">node
</ins>
</a>
s.
</p>
<p>
The
example
shows
two
<del class="diff-old">subjects
</del>
<ins class="diff-chg">nodes
</ins>
related
by
a
property
from
the
first
<del class="diff-old">subject:
</del>
<ins class="diff-chg">node:
</ins>
</p>
<del class="diff-old">  {
</del>
  <div class="example"><div class="example-title"><span>Example 47</span></div><pre class="example">{
...
  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;<span class="diff">knows</span>&quot;:
  {
    &quot;<span class="diff">@type</span>&quot;: &quot;<span class="diff">Person</span>&quot;,
    &quot;<span class="diff">name</span>&quot;: &quot;<span class="diff">Gregg Kellogg</span>&quot;,
  }
...
}
</pre>
</div>
<p>
A
<del class="diff-old">subject
</del>
<a class="tref internalDFN" title="node_definition" href="#dfn-node_definition">
<ins class="diff-chg">node
</ins>
definition
</a>,
like
the
one
used
above,
<em class="rfc2119" title="may">
may
</em>
be
used
in
any
value
position
in
the
body
of
a
JSON-LD
document.
</p>
</section>
<section id="named-graphs">
<h3>
<span class="secno">
<del class="diff-old">4.10
</del>
<ins class="diff-chg">4.11
</ins>
</span>
Named
Graphs
</h3>
<p>
The
<code>
@graph
</code>
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
keyword
</a>
is
used
to
express
a
set
of
JSON-LD
<del class="diff-old">subject
</del>
<a class="tref internalDFN" title="node_definition" href="#dfn-node_definition">
<ins class="diff-chg">node
</ins>
definition
</a>
s
that
may
not
be
directly
related
to
one
another
through
a
property.
The
mechanism
may
also
be
used
where
<a class="tref internalDFN" title="embedding" href="#dfn-embedding">
embedding
</a>
is
not
desirable
to
the
application.
For
example:
</p>
<del class="diff-old">  {
</del>
  <div class="example"><div class="example-title"><span>Example 48</span></div><pre class="example">{
  &quot;@context&quot;: ...,
  &quot;<span class="diff">@graph</span>&quot;:
  [
    {
      &quot;@id&quot;: &quot;http://manu.sporny.org/i/public&quot;,
      &quot;@type&quot;: &quot;foaf:Person&quot;,
      &quot;name&quot;: &quot;Manu Sporny&quot;,
      &quot;knows&quot;: &quot;http://greggkellogg.net/foaf#me&quot;
    },
    {
      &quot;@id&quot;: &quot;http://greggkellogg.net/foaf#me&quot;,
      &quot;@type&quot;: &quot;foaf:Person&quot;,
      &quot;name&quot;: &quot;Gregg Kellogg&quot;,
      &quot;knows&quot;: &quot;http://manu.sporny.org/i/public&quot;
    }
  ]
}
</pre>
</div>
<p>
In
this
case,
embedding
doesn't
work
as
each
<del class="diff-old">subject
</del>
<a class="tref internalDFN" title="node_definition" href="#dfn-node_definition">
<ins class="diff-chg">node
</ins>
definition
</a>
references
the
other.
Using
the
<code>
@graph
</code>
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
keyword
</a>
allows
multiple
resources
to
be
defined
within
an
<a class="tref internalDFN" title="array" href="#dfn-array">
array
</a>,
and
allows
the
use
of
a
shared
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>.
When
used
in
a
<a class="tref internalDFN" title="json_object" href="#dfn-json_object">
JSON
object
</a>
that
is
not
otherwise
a
<del class="diff-old">subject
</del>
<a class="tref internalDFN" title="node_definition" href="#dfn-node_definition">
<ins class="diff-chg">node
</ins>
definition
</a>,
this
describes
resources
in
the
<em>
default
graph
</em>.
This
is
equivalent
to
using
multiple
<del class="diff-old">subject
</del>
<a class="tref internalDFN" title="node_definition" href="#dfn-node_definition">
<ins class="diff-chg">node
</ins>
definitions
</a>
in
array
and
defining
the
<code>
@context
</code>
within
each
<del class="diff-old">subject
</del>
<a class="tref internalDFN" title="node_definition" href="#dfn-node_definition">
<ins class="diff-chg">node
</ins>
definition
</a>:
</p>
<del class="diff-old">  
</del>
  <div class="example"><div class="example-title"><span>Example 49</span></div><pre class="example"><span class="diff">[</span>
  {
    <span class="diff">&quot;@context&quot;: ...,</span>
    &quot;@id&quot;: &quot;http://manu.sporny.org/i/public&quot;,
    &quot;@type&quot;: &quot;foaf:Person&quot;,
    &quot;name&quot;: &quot;Manu Sporny&quot;,
    &quot;knows&quot;: &quot;http://greggkellogg.net/foaf#me&quot;
  },
  {
    <span class="diff">&quot;@context&quot;: ...,</span>
    &quot;@id&quot;: &quot;http://greggkellogg.net/foaf#me&quot;,
    &quot;@type&quot;: &quot;foaf:Person&quot;,
    &quot;name&quot;: &quot;Gregg Kellogg&quot;,
    &quot;knows&quot;: &quot;http://manu.sporny.org/i/public&quot;
  }
<span class="diff">
]
</span>
</pre>
</div>
<p>
JSON-LD
allows
you
to
<em>
name
</em>
things
on
the
Web
by
assigning
an
<code>
@id
</code>
to
them,
which
is
typically
an
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>.
This
notion
extends
to
the
ability
to
identify
graphs
in
the
same
manner.
A
developer
may
name
data
expressed
using
the
<code>
@graph
</code>
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
keyword
</a>
by
pairing
it
with
an
<code>
@id
</code>
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
keyword
</a>.
This
enables
the
developer
to
make
statements
about
a
<a class="tref internalDFN" title="linked_data_graph" href="#dfn-linked_data_graph">
linked
data
graph
</a>
itself,
rather
than
just
a
single
<del class="diff-old">subject
</del>
<a class="tref internalDFN" title="node" href="#dfn-node">
<ins class="diff-chg">node
</ins>
</a>.
</p>
<del class="diff-old">  {
  &quot;@context&quot;: ...,
</del>
  <div class="example"><div class="example-title"><span>Example 50</span></div><pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;: {
    &quot;asOf&quot;: &quot;http://purl.org/net/provenance/ns#accessedResource&quot;,
    &quot;Person&quot;: &quot;http://xmlns.com/foaf/0.1/Person&quot;,
    &quot;name&quot;: &quot;http://xmlns.com/foaf/0.1/name&quot;,
    &quot;knows&quot;: &quot;http://xmlns.com/foaf/0.1/knows&quot;,
    &quot;xsd&quot;: &quot;http://www.w3.org/2001/XMLSchema#&quot;
  },
</ins>
  <span class="diff">&quot;@id&quot;: &quot;http://example.org/graphs/73&quot;,
  &quot;asOf&quot;: { &quot;@value&quot;: &quot;2012-04-09&quot;, &quot;@type&quot;: &quot;xsd:date&quot; },
  &quot;@graph&quot;:</span>
  [
    {
      &quot;@id&quot;: &quot;http://manu.sporny.org/i/public&quot;,
<del class="diff-old">      &quot;@type&quot;: &quot;foaf:Person&quot;,
</del>
<ins class="diff-chg">      &quot;@type&quot;: &quot;Person&quot;,
</ins>
      &quot;name&quot;: &quot;Manu Sporny&quot;,
      &quot;knows&quot;: &quot;http://greggkellogg.net/foaf#me&quot;
    },
    {
      &quot;@id&quot;: &quot;http://greggkellogg.net/foaf#me&quot;,
<del class="diff-old">      &quot;@type&quot;: &quot;foaf:Person&quot;,
</del>
<ins class="diff-chg">      &quot;@type&quot;: &quot;Person&quot;,
</ins>
      &quot;name&quot;: &quot;Gregg Kellogg&quot;,
      &quot;knows&quot;: &quot;http://manu.sporny.org/i/public&quot;
    }
  ]
}
</pre>
</div>
<p>
The
example
above
expresses
a
<em>
named
</em>
<a class="tref internalDFN" title="linked_data_graph" href="#dfn-linked_data_graph">
linked
data
graph
</a>
that
is
identified
by
the
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
<code>
http://example.org/graphs/73
</code>.
That
graph
is
composed
of
the
statements
about
Manu
and
Gregg.
<del class="diff-old">Meta-data
</del>
<ins class="diff-chg">Metadata
</ins>
about
the
graph
itself
is
also
expressed
via
the
<code>
asOf
</code>
property,
which
specifies
when
the
information
was
retrieved
from
the
Web.
<ins class="diff-new">An
alternative
view
of
the
information
above
is
represented
in
table
form
below:
</ins>
</p>
<table class="example">
<thead>
<tr>
<th>
<ins class="diff-chg">Graph
</ins></th><th><ins class="diff-chg">
Subject
</ins></th><th><ins class="diff-chg">
Property
</ins></th><th><ins class="diff-chg">
Object
</ins></th><th><ins class="diff-chg">
Datatype
</ins></th></tr>
<del class="diff-old">Issue
3
</del>
</thead>
<tbody>
<tr>
<td>
<ins class="diff-chg">http://example.org/graphs/73
</ins></td><td><ins class="diff-chg">
http://example.org/graphs/73
</ins></td><td><ins class="diff-chg">
http://purl.org/net/provenance/ns#accessedResource
</ins></td><td><ins class="diff-chg">
2012-04-09
</ins></td><td><ins class="diff-chg">
http://www.w3.org/2001/XMLSchema#date
</ins></td></tr><tr><td><ins class="diff-chg">
http://example.org/graphs/73
</ins></td><td><ins class="diff-chg">
http://manu.sporny.org/i/public
</ins></td><td><ins class="diff-chg">
http://www.w3.org/2001/XMLSchema#type
</ins></td><td><ins class="diff-chg">
http://xmlns.com/foaf/0.1/Person
</ins></td><td>
</td>
</tr>
<tr>
<td>
<ins class="diff-chg">http://example.org/graphs/73
</ins></td><td><ins class="diff-chg">
http://manu.sporny.org/i/public
</ins></td><td><ins class="diff-chg">
http://xmlns.com/foaf/0.1/name
</ins></td><td><ins class="diff-chg">
Manu
Sporny
</ins></td><td>
<del class="diff-old">These
examples
could
all
have
TriG
definitions
of
their
RDF
results,
but
that
would
involve
adding
RDF
earlier
in
the
document.
</del>
</td>
</tr>
<tr>
<td>
<ins class="diff-chg">http://example.org/graphs/73
</ins></td><td><ins class="diff-chg">
http://manu.sporny.org/i/public
</ins></td><td><ins class="diff-chg">
http://xmlns.com/foaf/0.1/knows
</ins></td><td><ins class="diff-chg">
http://greggkellogg.net/foaf#me
</ins></td><td>
</td>
</tr>
<tr>
<td>
<ins class="diff-chg">http://example.org/graphs/73
</ins></td><td><ins class="diff-chg">
http://greggkellogg.net/foaf#me
</ins></td><td><ins class="diff-chg">
http://www.w3.org/2001/XMLSchema#type
</ins></td><td><ins class="diff-chg">
http://xmlns.com/foaf/0.1/Person
</ins></td><td></td></tr><tr><td><ins class="diff-chg">
http://example.org/graphs/73
</ins></td><td><ins class="diff-chg">
http://greggkellogg.net/foaf#me
</ins></td><td><ins class="diff-chg">
http://xmlns.com/foaf/0.1/name
</ins></td><td><ins class="diff-chg">
Gregg
Kellogg
</ins></td><td></td></tr><tr><td><ins class="diff-chg">
http://example.org/graphs/73
</ins></td><td><ins class="diff-chg">
http://greggkellogg.net/foaf#me
</ins></td><td><ins class="diff-chg">
http://xmlns.com/foaf/0.1/knows
</ins></td><td><ins class="diff-chg">
http://manu.sporny.org/i/public
</ins></td><td></td></tr></tbody></table></section><section id="identifying-unlabeled-nodes">
<h3>
<span class="secno">
<del class="diff-old">4.11
</del>
<ins class="diff-chg">4.12
</ins>
</span>
Identifying
Unlabeled
Nodes
</h3>
<p>
At
times,
it
becomes
necessary
to
be
able
to
express
information
without
being
able
to
specify
the
<del class="diff-old">subject.
</del>
<ins class="diff-chg">node.
</ins>
Typically,
this
type
of
node
is
called
an
<dfn title="unlabeled_node" id="dfn-unlabeled_node">
unlabeled
node
</dfn>
or
a
<dfn title="blank_node" id="dfn-blank_node">
blank
node
</dfn>
(see
[
<cite>
<a class="bibref" href="#bib-RDF-CONCEPTS">
RDF-CONCEPTS
</a>
</cite>
]
<cite>
<a href="http://www.w3.org/TR/rdf11-concepts/#section-blank-nodes">
Section
3.4:
Blank
Nodes
</a>
</cite>
).
In
JSON-LD,
<a class="tref internalDFN" title="unlabeled_node" href="#dfn-unlabeled_node">
unlabeled
node
</a>
identifiers
are
automatically
created
if
a
<del class="diff-old">subject
</del>
<ins class="diff-chg">node
</ins>
is
not
specified
using
the
<code>
@id
</code>
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
keyword
</a>.
However,
authors
may
provide
identifiers
for
<a class="tref internalDFN" title="unlabeled_node" href="#dfn-unlabeled_node">
unlabeled
nodes
</a>
by
using
the
special
<code>
_
</code>
(underscore)
<a class="tref internalDFN" title="prefix" href="#dfn-prefix">
prefix
</a>.
This
allows
one
to
reference
the
node
locally
within
the
document,
but
makes
it
impossible
to
reference
the
node
from
an
external
document.
The
<a class="tref internalDFN" title="unlabeled_node" href="#dfn-unlabeled_node">
unlabeled
node
</a>
identifier
is
scoped
to
the
document
in
which
it
is
used.
</p>
<del class="diff-old">{
</del>
<div class="example"><div class="example-title"><span>Example 51</span></div><pre class="example">{
...
  &quot;@id&quot;: &quot;<span class="diff">_:foo</span>&quot;,
...
}
</pre>
</div>
<p>
The
example
above
would
set
the
<del class="diff-old">subject
</del>
<ins class="diff-chg">node
</ins>
to
<code>
_:foo
</code>,
which
can
then
be
used
elsewhere
in
the
JSON-LD
document
to
refer
back
to
the
<a class="tref internalDFN" title="unlabeled_node" href="#dfn-unlabeled_node">
unlabeled
node
</a>.
If
a
developer
finds
that
they
refer
to
the
unlabeled
node
more
than
once,
they
should
consider
naming
the
node
using
a
de-referenceable
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
so
that
it
can
be
referenced
also
from
other
documents.
</p>
</section>
<section id="aliasing-keywords">
<h3>
<span class="secno">
<del class="diff-old">4.12
</del>
<ins class="diff-chg">4.13
</ins>
</span>
Aliasing
Keywords
</h3>
<p>
Each
of
the
JSON-LD
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
keywords
</a>,
except
for
<code>
@context
</code>,
<em class="rfc2119" title="may">
may
</em>
be
aliased
to
application-specific
keywords.
This
feature
allows
legacy
JSON
content
to
be
utilized
by
JSON-LD
by
re-using
JSON
keys
that
already
exist
in
legacy
documents.
This
feature
also
allows
developers
to
design
domain-specific
implementations
using
only
the
JSON-LD
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>.
</p>
<del class="diff-old">{
</del>
<div class="example"><div class="example-title"><span>Example 52</span></div><pre class="example">{
  &quot;@context&quot;:
  {
     <span class="diff">&quot;url&quot;: &quot;@id&quot;</span>,
     <span class="diff">&quot;a&quot;: &quot;@type&quot;</span>,
     &quot;name&quot;: &quot;http://schema.org/name&quot;
  },
  &quot;<span class="diff">url</span>&quot;: &quot;http://example.com/about#gregg&quot;,
  &quot;<span class="diff">a</span>&quot;: &quot;http://schema.org/Person&quot;,
  &quot;name&quot;: &quot;Gregg Kellogg&quot;
}
</pre>
</div>
<p>
In
the
example
above,
the
<code>
@id
</code>
and
<code>
@type
</code>
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
keywords
</a>
have
been
given
the
aliases
<strong>
url
</strong>
and
<strong>
a
</strong>,
respectively.
</p>
</section>
<section id="expanded-document-form">
<h3>
<span class="secno">
<del class="diff-old">4.13
</del>
<ins class="diff-chg">4.14
</ins>
</span>
Expanded
Document
Form
</h3>
<p>
The
JSON-LD
API
[
<cite>
<a class="bibref" href="#bib-JSON-LD-API">
JSON-LD-API
</a>
</cite>
]
defines
an
method
for
<em>
expanding
</em>
a
JSON-LD
document.
Expansion
is
the
process
of
taking
a
JSON-LD
document
and
applying
a
<code>
@context
</code>
such
that
all
IRIs,
types,
and
values
are
expanded
so
that
the
<code>
@context
</code>
is
no
longer
necessary.
</p>
<p>
For
example,
assume
the
following
JSON-LD
input
document:
</p>
<del class="diff-old">{
</del>
<div class="example"><div class="example-title"><span>Example 53</span></div><pre class="example">{
   &quot;@context&quot;:
   {
      &quot;name&quot;: &quot;http://xmlns.com/foaf/0.1/name&quot;,
      &quot;homepage&quot;: {
        &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/homepage&quot;,
<del class="diff-old">        &quot;@type&quot;, &quot;@id&quot;
</del>
<ins class="diff-chg">        &quot;@type&quot;: &quot;@id&quot;
</ins>
      }
   },
   &quot;name&quot;: &quot;Manu Sporny&quot;,
   &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;
}
</pre>
</div>
<p>
Running
the
JSON-LD
Expansion
algorithm
against
the
JSON-LD
input
document
provided
above
would
result
in
the
following
output:
</p>
<del class="diff-old">[
</del>
<div class="example"><div class="example-title"><span>Example 54</span></div><pre class="example">[
  {
    &quot;http://xmlns.com/foaf/0.1/name&quot;: [
      { &quot;@value&quot;: &quot;Manu Sporny&quot; }
    ],
    &quot;http://xmlns.com/foaf/0.1/homepage&quot;: [
      { &quot;@id&quot;: &quot;http://manu.sporny.org/&quot; }
    ]
  }
]
</pre>
</div>
<p>
Expanded
document
form
is
useful
when
an
application
has
to
process
input
data
in
a
deterministic
form.
It
has
been
optimized
to
ensure
that
the
code
that
developers
have
to
write
is
minimized
compared
to
the
code
that
would
have
to
be
written
to
operate
on
<del class="diff-old">compact
document
form
</del>
<a href="#compact-document-form" class="sec-ref">
<span class="secno">
<ins class="diff-chg">4.15
</ins></span><span class="sec-title"><ins class="diff-chg">
Compact
Document
Form
</ins></span>
</a>.
</p>
</section>
<section id="compact-document-form">
<h3>
<span class="secno">
<del class="diff-old">4.14
</del>
<ins class="diff-chg">4.15
</ins>
</span>
Compact
Document
Form
</h3>
<p>
The
JSON-LD
API
[
<cite>
<a class="bibref" href="#bib-JSON-LD-API">
JSON-LD-API
</a>
</cite>
]
defines
a
method
for
<em>
compacting
</em>
a
JSON-LD
document.
Compaction
is
the
process
of
taking
a
JSON-LD
document
and
applying
a
context
such
that
the
most
compact
form
of
the
document
is
generated.
JSON
is
typically
expressed
in
a
very
compact,
key-value
format.
That
is,
full
IRIs
are
rarely
used
as
keys.
At
times,
a
JSON-LD
document
may
be
received
that
is
not
in
its
most
compact
form.
JSON-LD,
via
the
API,
provides
a
way
to
compact
a
JSON-LD
document.
</p>
<p>
For
example,
assume
the
following
JSON-LD
input
document:
</p>
<del class="diff-old">[
</del>
<div class="example"><div class="example-title"><span>Example 55</span></div><pre class="example">[
  {
    &quot;http://xmlns.com/foaf/0.1/name&quot;: [ &quot;Manu Sporny&quot; ],
    &quot;http://xmlns.com/foaf/0.1/homepage&quot;: [
      {
       &quot;@id&quot;: &quot;http://manu.sporny.org/&quot;
      }
    ]
  }
]
</pre>
</div>
<p>
Additionally,
assume
the
following
developer-supplied
JSON-LD
context:
</p>
<del class="diff-old">{
</del>
<div class="example"><div class="example-title"><span>Example 56</span></div><pre class="example">{
  &quot;@context&quot;: {
    &quot;name&quot;: &quot;http://xmlns.com/foaf/0.1/name&quot;,
    &quot;homepage&quot;: {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/homepage&quot;,
      &quot;@type&quot;: &quot;@id&quot;
    }
  }
}
</pre>
</div>
<p>
Running
the
JSON-LD
Compaction
algorithm
given
the
context
supplied
above
against
the
JSON-LD
input
document
provided
above
would
result
in
the
following
output:
</p>
<del class="diff-old">{
</del>
<div class="example"><div class="example-title"><span>Example 57</span></div><pre class="example">{
  &quot;@context&quot;: {
    &quot;name&quot;: &quot;http://xmlns.com/foaf/0.1/name&quot;,
    &quot;homepage&quot;: {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/homepage&quot;,
      &quot;@type&quot;: &quot;@id&quot;
    }
  },
  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;
}
</pre>
</div>
<p>
The
compaction
algorithm
enables
a
developer
to
map
any
document
into
an
application-specific
compacted
form
by
first
<del class="diff-old">expanding
the
document
</del>
<a href="#expanded-document-form" class="sec-ref">
<span class="secno">
<ins class="diff-chg">4.14
</ins></span><span class="sec-title"><ins class="diff-chg">
Expanded
Document
Form
</ins></span>
</a>.
While
the
context
provided
above
mapped
<code>
http://xmlns.com/foaf/0.1/name
</code>
to
<strong>
name
</strong>,
it
could
have
also
mapped
it
to
any
arbitrary
string
provided
by
the
developer.
This
powerful
mechanism,
along
with
another
JSON-LD
API
technique
called
<em>
framing
</em>,
allows
the
developer
to
re-shape
the
incoming
JSON
data
into
a
format
that
is
optimized
for
their
application.
</p>
</section>
</section>
<section class="appendix normative" id="json-ld-grammar">
<h2>
<span class="secno">
A.
</span>
JSON-LD
<del class="diff-old">Authoring
Guidelines
</del>
<ins class="diff-chg">Grammar
</ins>
</h2>
<em>
<ins class="diff-new">This
section
is
normative
</ins></em><p class="issue resolved" data-number="114"><ins class="diff-new">
This
section
is
an
attempt
to
formalize
a
normative
grammar
for
JSON-LD.
</ins></p>
<p>
<del class="diff-old">Since
</del>
<ins class="diff-chg">This
appendix
restates
the
syntactic
conventions
described
in
</ins>
the
<ins class="diff-new">previous
sections
more
formally.
</ins></p><p><ins class="diff-new">
A
</ins>
JSON-LD
<del class="diff-old">syntax
is
</del>
<ins class="diff-chg">processor
</ins><em class="rfc2119" title="should"><ins class="diff-chg">
should
</ins></em><ins class="diff-chg">
attempt
to
process
non-conforming
JSON-LD
documents.
Conformance
violations
</ins><em class="rfc2119" title="must"><ins class="diff-chg">
must
</ins></em><ins class="diff-chg">
be
reported
through
</ins>
a
<del class="diff-old">subset
of
</del>
<ins class="diff-chg">conformance
violation
callback
mechanism
defined
in
</ins>
the
<del class="diff-old">JSON
syntax,
it
follows
that
all
valid
</del>
<ins class="diff-chg">[
</ins><cite><a class="bibref" href="#bib-JSON-LD-API"><ins class="diff-chg">
JSON-LD-API
</ins></a></cite><ins class="diff-chg">
].
</ins></p><p><ins class="diff-chg">
For
a
</ins>
JSON-LD
<del class="diff-old">documents
are
valid
JSON
documents.
It
also
means
that
an
invalid
JSON
</del>
document
<del class="diff-old">can
never
</del>
<ins class="diff-chg">to
be
conforming,
it
</ins><em class="rfc2119" title="must"><ins class="diff-chg">
must
</ins></em>
be
a
valid
<ins class="diff-new">JSON
document
as
described
in
[
</ins><cite><a class="bibref" href="#bib-RFC4627"><ins class="diff-new">
RFC4627
</ins></a></cite><ins class="diff-new">
].
</ins></p><p>
JSON-LD
<del class="diff-old">document.
Furthermore,
JSON-LD
places
</del>
<ins class="diff-chg">introduces
</ins>
a
number
of
<del class="diff-old">restrictions
on
</del>
<ins class="diff-chg">keywords
of
</ins>
the
<del class="diff-old">JSON
syntax
in
order
to
define
</del>
<ins class="diff-chg">form
'
</ins><code><ins class="diff-chg">
@
</ins></code><ins class="diff-chg">
'
followed
by
</ins>
a
set
of
<del class="diff-old">authoring
guidelines
that
are
used
to
express
well-formed
</del>
<ins class="diff-chg">one
or
more
lower
case
alphabetic
characters
(
</ins><code><ins class="diff-chg">
@[a-z]+
</ins></code><ins class="diff-chg">
).
</ins>
JSON-LD
<del class="diff-old">documents.
At
times,
even
if
these
guidelines
are
violated,
</del>
<ins class="diff-chg">documents
</ins><em class="rfc2119" title="should not"><ins class="diff-chg">
should
not
</ins></em><ins class="diff-chg">
define
terms
beginning
with
'
</ins><code><ins class="diff-chg">
@
</ins></code><ins class="diff-chg">
'.
(See
</ins><a href="#syntax-tokens-and-keywords" class="sec-ref"><span class="secno"><ins class="diff-chg">
3.4
</ins></span><span class="sec-title"><ins class="diff-chg">
Syntax
Tokens
and
Keywords
</ins></span></a><ins class="diff-chg">
for
</ins>
a
<ins class="diff-new">complete
definition
of
</ins>
JSON-LD
<del class="diff-old">processor
will
do
its
best
to
recover
from
the
mistake
and
will
deterministically
transform
the
author's
markup
into
well-formed
JSON-LD.
</del>
<ins class="diff-chg">keywords).
</ins>
</p>
<div class="note">
<div class="note-title">
<span>
<del class="diff-old">Issue
4
</del>
<ins class="diff-chg">Note
</ins>
</span>
</div>
<p class="">
The
<del class="diff-old">final
details
of
the
guidelines
are
still
being
discussed
(
ISSUE-114
</del>
<ins class="diff-chg">JSON-LD
context
allows
</ins><a class="tref internalDFN" title="keyword" href="#dfn-keyword"><ins class="diff-chg">
keywords
</ins>
</a>
<del class="diff-old">),
as
well
as
</del>
<ins class="diff-chg">to
be
aliased
within
</ins>
the
<del class="diff-old">best
mechanism
</del>
<a class="tref internalDFN" title="active_context" href="#dfn-active_context">
<ins class="diff-chg">active
context
</ins></a>.<ins class="diff-chg">
Whenever
a
</ins><a class="tref internalDFN" title="keyword" href="#dfn-keyword"><ins class="diff-chg">
keyword
</ins></a><ins class="diff-chg">
is
discussed,
this
is
also
understood
</ins>
to
<del class="diff-old">express
these
restrictions.
EBNF
doesn't
quite
capture
what
these
guidelines
are
attempting
</del>
<ins class="diff-chg">apply
</ins>
to
<del class="diff-old">do
-
which
is
strongly
express
what
constitutes
a
well-formed
JSON-LD
document.
</del>
<ins class="diff-chg">an
alias
for
that
</ins><a class="tref internalDFN" title="keyword" href="#dfn-keyword"><ins class="diff-chg">
keyword
</ins></a>
For
<ins class="diff-new">example,
if
</ins>
the
<del class="diff-old">time
being,
</del>
<a class="tref internalDFN" title="active_context" href="#dfn-active_context">
<ins class="diff-chg">active
context
</ins></a><ins class="diff-chg">
defines
the
</ins><a class="tref internalDFN" title="term" href="#dfn-term"><ins class="diff-chg">
term
</ins></a><code><ins class="diff-chg">
id
</ins></code><ins class="diff-chg">
as
an
alias
for
</ins><code><ins class="diff-chg">
@id
</ins></code>,<ins class="diff-chg">
that
alias
may
be
legitimately
used
as
</ins>
a
<del class="diff-old">simple
list
of
plain
English
guidelines
</del>
<ins class="diff-chg">substitution
for
</ins><code><ins class="diff-chg">
@id
</ins></code>.<ins class="diff-chg">
Note
that
</ins><a class="tref internalDFN" title="keyword" href="#dfn-keyword"><ins class="diff-chg">
keyword
</ins></a><ins class="diff-chg">
aliases
</ins>
are
<del class="diff-old">provided.
Issue
5
Per
Andy
S's
comment
,
consider
making
this
a
normative
syntax
definition
along
with
EBNF.
</del>
<ins class="diff-chg">not
expanded
during
context
processing.
</ins>
</p>
</div>
<p>
A
JSON-LD
document
is
<del class="diff-old">composed
of
</del>
<ins class="diff-chg">either
a
</ins>
a
single
<del class="diff-old">subject
</del>
<a class="tref internalDFN" title="node_definition" href="#dfn-node_definition">
<ins class="diff-chg">node
</ins>
definition
</a>
or
<del class="diff-old">an
</del>
<ins class="diff-chg">a
JSON
</ins>
<a class="tref internalDFN" title="array" href="#dfn-array">
array
</a>
<ins class="diff-new">containing
a
set
</ins>
of
<del class="diff-old">subject
</del>
<ins class="diff-chg">one
or
more
</ins><a class="tref internalDFN" title="node_definition" href="#dfn-node_definition"><ins class="diff-chg">
node
</ins>
definitions
</a>.
<del class="diff-old">The
value
of
@id
must
be
a
term
,
</del>
</p>
<div class="example"><div class="example-title"><span>Example 58</span>: Simple node definition</div><pre class="example">{
<ins class="diff-chg">  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;,
  &quot;depiction&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;
}
</ins></pre></div><div class="example"><div class="example-title"><span>Example 59</span>: Array of node definitions</div><pre class="example">[<ins class="diff-chg">
  {
    &quot;name&quot;: &quot;Manu Sporny&quot;,
    &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;,
    &quot;depiction&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;
  }, {
    &quot;name&quot;: &quot;Gregg Kellogg&quot;,
    &quot;homepage&quot;: &quot;http://greggkellogg.net/&quot;,
    &quot;depiction&quot;: &quot;http://twitter.com/account/profile_image/gkellogg&quot;
  }
]
</ins></pre></div><section id="grammar-node-definition"><h3><span class="secno"><ins class="diff-chg">
A.1
</ins></span><ins class="diff-chg">
Node
Definition
</ins></h3><p><ins class="diff-chg">
A
</ins><a class="tref internalDFN" title="node_definition" href="#dfn-node_definition"><ins class="diff-chg">
node
definition
</ins></a><ins class="diff-chg">
is
</ins>
a
<del class="diff-old">compact
</del>
<a class="tref internalDFN" title="json_object" href="#dfn-json_object">
<ins class="diff-chg">JSON
object
</ins></a><ins class="diff-chg">
containing
one
or
more
key-value
pairs.
Keys
are
</ins><a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
<del class="diff-old">,
or
an
</del>
</a>
<ins class="diff-chg">s,
</ins><a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri"><ins class="diff-chg">
compact
</ins>
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
<del class="diff-old">.
</del>
</a>
<ins class="diff-chg">s,
</ins><a class="tref internalDFN" title="term" href="#dfn-term"><ins class="diff-chg">
term
</ins></a><ins class="diff-chg">
s
defined
within
the
</ins><a class="tref internalDFN" title="active_context" href="#dfn-active_context"><ins class="diff-chg">
active
context
</ins></a>,<ins class="diff-chg">
or
one
of
the
following
keywords:
</ins></p><ul>
<li>
<del class="diff-old">An
@id
keyword
and
a
</del>
<code>
<del class="diff-old">@language
keyword
must
not
exist
in
the
same
JSON
object
.
</del>
<ins class="diff-chg">@context
</ins></code>,
</li>
<li>
<del class="diff-old">An
@id
keyword
and
a
</del>
<code>
<del class="diff-old">@container
keyword
must
not
exist
in
the
same
JSON
object
.
</del>
<ins class="diff-chg">@graph
</ins></code>,
</li>
<li>
<del class="diff-old">A
subject
definition
may
contain
a
</del>
<code>
<del class="diff-old">@context
property.
</del>
<ins class="diff-chg">@id
</ins></code>,<ins class="diff-chg">
or
</ins>
</li>
<li>
<del class="diff-old">A
@context
value
must
not
contain
an
embedded
</del>
<code>
<del class="diff-old">@context
</del>
<ins class="diff-chg">@type
</ins>
</code>
<del class="diff-old">definition.
</del>
</li>
<del class="diff-old">The
value
associated
with
</del>
</ul>
<p>
<ins class="diff-chg">If
the
</ins><a class="tref internalDFN" title="node_definition" href="#dfn-node_definition"><ins class="diff-chg">
node
definition
</ins></a><ins class="diff-chg">
contains
</ins>
the
<code>
@context
</code>
<del class="diff-old">keyword
</del>
<ins class="diff-chg">key,
its
value
</ins>
<em class="rfc2119" title="must">
must
</em>
be
<ins class="diff-new">one
of
the
following:
</ins></p><ul><li>
a
<a class="tref internalDFN" title="string" href="#dfn-string">
string
<del class="diff-old">expanding
to
an
</del>
</a>
<ins class="diff-chg">with
the
lexical
form
of
</ins>
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>,
</li>
<li>
a
<a class="tref internalDFN" title="json_object" href="#dfn-json_object">
JSON
object
</a>
<ins class="diff-new">conforming
the
the
syntax
requirements
stated
in
</ins><a href="#grammar-context" class="sec-ref"><span class="secno"><ins class="diff-new">
A.6
</ins></span><span class="sec-title"><ins class="diff-new">
Context
Definition
</ins></span>
</a>,
<del class="diff-old">null,
</del>
or
</li>
<li>
an
<a class="tref internalDFN" title="array" href="#dfn-array">
array
</a>
<del class="diff-old">containing
a
combination
</del>
<ins class="diff-chg">composed
of
any
number
</ins>
of
the
<del class="diff-old">allowed
values.
</del>
<ins class="diff-chg">previous
two
expressions.
</ins>
</li>
<del class="diff-old">The
value
associated
with
</del>
</ul>
<div class="example"><div class="example-title"><span>Example 60</span>: Node definition with external context</div><pre class="example">{
  <span class="diff">&quot;@context&quot;: &quot;http://json-ld.org/contexts/person.jsonld&quot;</span>,
<ins class="diff-chg">  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;,
  &quot;depiction&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;
}
</ins></pre></div><p><ins class="diff-chg">
See
</ins><a href="#node-identifiers" class="sec-ref"><span class="secno"><ins class="diff-chg">
3.8
</ins></span><span class="sec-title"><ins class="diff-chg">
Node
Identifiers
</ins></span></a>,<a href="#compact-iris" class="sec-ref"><span class="secno"><ins class="diff-chg">
4.1
</ins></span><span class="sec-title"><ins class="diff-chg">
Compact
IRIs
</ins></span></a>,<ins class="diff-chg">
and
</ins><a href="#identifying-unlabeled-nodes" class="sec-ref"><span class="secno"><ins class="diff-chg">
4.12
</ins></span><span class="sec-title"><ins class="diff-chg">
Identifying
Unlabeled
Nodes
</ins></span></a><ins class="diff-chg">
for
further
discussion
on
</ins><code><ins class="diff-chg">
@id
</ins></code><ins class="diff-chg">
values.
</ins></p><p><ins class="diff-chg">
If
the
</ins><a class="tref internalDFN" title="node_definition" href="#dfn-node_definition"><ins class="diff-chg">
node
definition
</ins></a><ins class="diff-chg">
contains
</ins>
the
<del class="diff-old">keys
used
in
a
</del>
<code>
<del class="diff-old">@context
</del>
<ins class="diff-chg">@id
</ins>
</code>
<ins class="diff-new">key,
it's
value
</ins>
<em class="rfc2119" title="must">
must
</em>
be
a
<del class="diff-old">null
,
an
</del>
<a class="tref internalDFN" title="string" href="#dfn-string">
<ins class="diff-chg">string
</ins></a><ins class="diff-chg">
having
the
lexical
form
of
</ins>
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>,
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
<ins class="diff-new">compact
</ins><abbr title="Internationalized Resource Identifier"><ins class="diff-new">
IRI
</ins></abbr></a><ins class="diff-new">
(including
</ins><a class="tref internalDFN" title="unlabeled_node" href="#dfn-unlabeled_node"><ins class="diff-new">
unlabeled
node
</ins></a><ins class="diff-new">
),
</ins>
or
a
<del class="diff-old">JSON
object
.
For
each
value
that
is
a
JSON
object
</del>
<a class="tref internalDFN" title="term" href="#dfn-term">
<ins class="diff-chg">term
</ins>
</a>
<del class="diff-old">that
is
associated
with
a
key
</del>
<ins class="diff-chg">defined
</ins>
in
<del class="diff-old">a
@context
:
</del>
<ins class="diff-chg">the
</ins><a class="tref internalDFN" title="active_context" href="#dfn-active_context"><ins class="diff-chg">
active
context
</ins></a><ins class="diff-chg">
expanding
into
an
</ins><a class="tref internalDFN" title="iri" href="#dfn-iri">
<del class="diff-old">@id
and
</del>
<abbr title="Internationalized Resource Identifier">
<ins class="diff-chg">IRI
</ins></abbr></a><ins class="diff-chg">
or
an
</ins><a class="tref internalDFN" title="unlabeled_node" href="#dfn-unlabeled_node"><ins class="diff-chg">
unlabeled
node
</ins></a>.</p><div class="example"><div class="example-title"><span>Example 61</span>: Node definition with @id</div><pre class="example">{<ins class="diff-chg">
  &quot;@context&quot;: &quot;http://json-ld.org/contexts/person.jsonld&quot;,
</ins>  <span class="diff">&quot;@id&quot;: &quot;http://manu.sporny.org/i/public&quot;</span>,<ins class="diff-chg">
  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;,
  &quot;depiction&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;
}
</ins></pre></div><p><ins class="diff-chg">
If
the
</ins><a class="tref internalDFN" title="node_definition" href="#dfn-node_definition"><ins class="diff-chg">
node
definition
</ins></a><ins class="diff-chg">
contains
the
</ins>
<code>
@type
</code>
<ins class="diff-new">key,
it's
value
</ins>
<em class="rfc2119" title="must">
must
</em>
be
<del class="diff-old">an
</del>
<ins class="diff-chg">either
a
</ins><a class="tref internalDFN" title="string" href="#dfn-string"><ins class="diff-chg">
string
</ins></a><ins class="diff-chg">
having
the
lexical
form
of
</ins><a class="tref internalDFN" title="absolute_iri" href="#dfn-absolute_iri"><ins class="diff-chg">
absolute
</ins><abbr title="Internationalized Resource Identifier"><ins class="diff-chg">
IRI
</ins></abbr>
</a>,
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
<ins class="diff-new">compact
</ins>
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>,
<ins class="diff-new">a
</ins><a class="tref internalDFN" title="term" href="#dfn-term"><ins class="diff-new">
term
</ins>
</a>
<del class="diff-old">or
null
</del>
<ins class="diff-chg">defined
in
the
</ins><a class="tref internalDFN" title="active_context" href="#dfn-active_context"><ins class="diff-chg">
active
context
</ins></a><ins class="diff-chg">
expanding
into
an
</ins><a class="tref internalDFN" title="absolute_iri" href="#dfn-absolute_iri"><ins class="diff-chg">
absolute
</ins><abbr title="Internationalized Resource Identifier"><ins class="diff-chg">
IRI
</ins></abbr>
</a>,
<ins class="diff-new">or
an
</ins><a class="tref internalDFN" title="array" href="#dfn-array"><ins class="diff-new">
array
</ins></a><ins class="diff-new">
of
any
of
these.
</ins></p><p><ins class="diff-new">
A
JSON-LD
processor
</ins><em class="rfc2119" title="should"><ins class="diff-new">
should
</ins></em><ins class="diff-new">
process
non-conforming
documents
having
</ins>
<code>
<del class="diff-old">@container
</del>
<ins class="diff-chg">@type
</ins>
</code>
<ins class="diff-new">values
including
</ins><a class="tref internalDFN" title="node_definition" href="#dfn-node_definition"><ins class="diff-new">
node
definition
</ins></a><ins class="diff-new">
or
</ins><a class="tref internalDFN" title="node_reference" href="#dfn-node_reference"><ins class="diff-new">
node
reference
</ins></a><ins class="diff-new">
entries
but
</ins>
<em class="rfc2119" title="must">
must
</em>
<del class="diff-old">be
associated
with
a
</del>
<ins class="diff-chg">discard
everything
except
for
the
</ins>
value
of
<del class="diff-old">either
</del>
<ins class="diff-chg">the
</ins>
<code>
<del class="diff-old">@set
</del>
<ins class="diff-chg">@id
</ins>
</code>
<del class="diff-old">or
@list
.
</del>
<ins class="diff-chg">key.
</ins></p><div class="example"><div class="example-title"><span>Example 62</span>: Node definition with @type</div><pre class="example">{<ins class="diff-chg">
  &quot;@context&quot;: &quot;http://json-ld.org/contexts/person.jsonld&quot;,
  &quot;@id&quot;: &quot;http://manu.sporny.org/i/public&quot;,
</ins>  <span class="diff">&quot;@type&quot;: &quot;Person&quot;</span>,<ins class="diff-chg">
  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;,
  &quot;depiction&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;
}
</ins></pre>
</div>
<p>
<ins class="diff-new">See
</ins><a href="#specifying-the-type" class="sec-ref"><span class="secno"><ins class="diff-new">
3.9
</ins></span><span class="sec-title"><ins class="diff-new">
Specifying
the
Type
</ins></span></a><ins class="diff-new">
for
further
discussion
on
</ins>
<code>
<del class="diff-old">@language
</del>
<ins class="diff-chg">@type
</ins>
</code>
<ins class="diff-new">values.
</ins></p><p><ins class="diff-new">
If
the
</ins><a class="tref internalDFN" title="node_definition" href="#dfn-node_definition"><ins class="diff-new">
node
definition
</ins></a><ins class="diff-new">
contains
the
</ins><code><ins class="diff-new">
@graph
</ins></code><ins class="diff-new">
key,
it's
value
</ins>
<em class="rfc2119" title="must">
must
</em>
be
a
<del class="diff-old">string
expressed
in
[
BCP47
</del>
<a class="tref internalDFN" title="node_definition" href="#dfn-node_definition">
<ins class="diff-chg">node
definition
</ins>
</a>
<del class="diff-old">]
</del>
or
<ins class="diff-new">an
</ins><a class="tref internalDFN" title="array" href="#dfn-array"><ins class="diff-new">
array
</ins></a><ins class="diff-new">
of
zero
or
more
</ins><a class="tref internalDFN" title="node_definition" href="#dfn-node_definition"><ins class="diff-new">
node
definitions
</ins></a>.<ins class="diff-new">
If
the
</ins><a class="tref internalDFN" title="node_definition" href="#dfn-node_definition"><ins class="diff-new">
node
definition
</ins></a><ins class="diff-new">
contains
an
</ins>
<code>
<del class="diff-old">null
.
Any
</del>
<ins class="diff-chg">@id
</ins></code><ins class="diff-chg">
keyword,
its
value
is
used
as
the
label
of
a
named
graph.
</ins></p><div class="note"><div class="note-title"><span><ins class="diff-chg">
Note
</ins></span></div><p class=""><ins class="diff-chg">
As
a
special
case,
if
the
</ins><a class="tref internalDFN" title="json_object" href="#dfn-json_object"><ins class="diff-chg">
JSON
object
</ins></a><ins class="diff-chg">
contains
no
keys
</ins>
other
<del class="diff-old">property
must
</del>
<ins class="diff-chg">than
</ins><code><ins class="diff-chg">
@graph
</ins></code><ins class="diff-chg">
and
</ins><code><ins class="diff-chg">
@context
</ins></code>,<ins class="diff-chg">
and
the
</ins><a class="tref internalDFN" title="json_object" href="#dfn-json_object"><ins class="diff-chg">
JSON
object
</ins></a><ins class="diff-chg">
is
the
root
of
the
JSON-LD
document,
the
</ins><a class="tref internalDFN" title="json_object" href="#dfn-json_object"><ins class="diff-chg">
JSON
object
</ins></a><ins class="diff-chg">
is
not
treated
as
a
</ins><a class="tref internalDFN" title="node_definition" href="#dfn-node_definition"><ins class="diff-chg">
node
definition
</ins></a><ins class="diff-chg">
;
this
is
used
as
a
way
of
defining
</ins><a class="tref internalDFN" title="node_definition" href="#dfn-node_definition"><ins class="diff-chg">
node
definitions
</ins></a><ins class="diff-chg">
that
may
not
form
a
connected
graph.
This
allows
a
</ins><a class="tref internalDFN" title="context" href="#dfn-context"><ins class="diff-chg">
context
</ins></a><ins class="diff-chg">
to
</ins>
be
<del class="diff-old">ignored
</del>
<ins class="diff-chg">defined
which
is
shared
</ins>
by
<del class="diff-old">a
</del>
<ins class="diff-chg">all
of
the
constituent
</ins><a class="tref internalDFN" title="node_definition" href="#dfn-node_definition"><ins class="diff-chg">
node
definitions
</ins></a>.</p></div><div class="example"><div class="example-title"><span>Example 63</span>: Multiple node definitions with a single context using @graph</div><pre class="example">{<ins class="diff-chg">
  &quot;@context&quot;: ...,
  &quot;<span class="diff">@graph</span>&quot;:
  [
    {
      &quot;@id&quot;: &quot;http://manu.sporny.org/i/public&quot;,
      &quot;@type&quot;: &quot;foaf:Person&quot;,
      &quot;name&quot;: &quot;Manu Sporny&quot;,
      &quot;knows&quot;: &quot;http://greggkellogg.net/foaf#me&quot;
    },
    {
      &quot;@id&quot;: &quot;http://greggkellogg.net/foaf#me&quot;,
      &quot;@type&quot;: &quot;foaf:Person&quot;,
      &quot;name&quot;: &quot;Gregg Kellogg&quot;,
      &quot;knows&quot;: &quot;http://manu.sporny.org/i/public&quot;
    }
  ]
}
</ins></pre></div><p><ins class="diff-chg">
See
</ins><a href="#named-graphs" class="sec-ref"><span class="secno"><ins class="diff-chg">
4.11
</ins></span><span class="sec-title"><ins class="diff-chg">
Named
Graphs
</ins></span></a><ins class="diff-chg">
for
further
discussion
on
</ins><code><ins class="diff-chg">
@graph
</ins></code><ins class="diff-chg">
values.
</ins></p><p><ins class="diff-chg">
A
</ins>
JSON-LD
<del class="diff-old">processor
and
</del>
<ins class="diff-chg">document
</ins><em class="rfc2119" title="must not"><ins class="diff-chg">
must
not
</ins></em><ins class="diff-chg">
contain
any
</ins><a class="tref internalDFN" title="keyword" href="#dfn-keyword"><ins class="diff-chg">
keyword
</ins></a><ins class="diff-chg">
or
alias
that
expands
to
another
keyword.
</ins></p><p><ins class="diff-chg">
Other
keys
</ins>
<em class="rfc2119" title="must">
must
</em>
<ins class="diff-new">expand
to
an
</ins><a class="tref internalDFN" title="absolute_iri" href="#dfn-absolute_iri"><ins class="diff-new">
absolute
</ins><abbr title="Internationalized Resource Identifier"><ins class="diff-new">
IRI
</ins></abbr></a><ins class="diff-new">
using
the
</ins><a class="tref internalDFN" title="active_context" href="#dfn-active_context"><ins class="diff-new">
active
context
</ins></a>.<ins class="diff-new">
The
values
associated
with
these
keys
may
</ins>
be
<del class="diff-old">preserved
in
compaction
and
framing.
</del>
<ins class="diff-chg">any
of
the
following:
</ins></p><ul><li><a class="tref internalDFN" title="string" href="#dfn-string"><ins class="diff-chg">
string
</ins></a>,
</li>
<li>
<a class="tref internalDFN" title="number" href="#dfn-number">
<ins class="diff-chg">number
</ins></a>,
</li>
<li>
<del class="diff-old">A
subject
</del>
<a class="tref internalDFN" title="true" href="#dfn-true">
<ins class="diff-chg">true
</ins></a>,</li><li><a class="tref internalDFN" title="false" href="#dfn-false"><ins class="diff-chg">
false
</ins></a>,</li><li><a class="tref internalDFN" title="null" href="#dfn-null"><ins class="diff-chg">
null
</ins></a>,</li><li><a class="tref internalDFN" title="node_reference" href="#dfn-node_reference"><ins class="diff-chg">
node
reference
</ins></a>,</li><li><a class="tref internalDFN" title="node_definition" href="#dfn-node_definition"><ins class="diff-chg">
node
</ins>
definition
<del class="diff-old">may
have
an
@graph
property.
</del>
</a>,
</li>
<li>
<del class="diff-old">The
</del>
<a class="tref internalDFN" title="typed_value" href="#dfn-typed_value">
<ins class="diff-chg">typed
</ins>
value
<del class="diff-old">of
a
</del>
</a>,
</li>
<li>
<a class="tref internalDFN" title="language-tagged_string" href="#dfn-language-tagged_string">
<ins class="diff-chg">language-tagged
string
</ins></a>,</li><li>
<code>
<del class="diff-old">@graph
</del>
<ins class="diff-chg">@set
</ins></code><ins class="diff-chg">
or
</ins><code><ins class="diff-chg">
@list
</ins>
</code>
<del class="diff-old">property
must
be
a
subject
</del>
definition
<ins class="diff-new">(see
</ins><a href="#sets-and-lists" class="sec-ref"><span class="secno"><ins class="diff-new">
4.9
</ins></span><span class="sec-title"><ins class="diff-new">
Sets
and
Lists
</ins></span>
</a>
<del class="diff-old">or
</del>
<ins class="diff-chg">),
</ins></li><li>
an
<a class="tref internalDFN" title="array" href="#dfn-array">
array
<del class="diff-old">of
</del>
</a>
zero
or
more
<del class="diff-old">subject
definitions
.
</del>
<ins class="diff-chg">of
these,
or
</ins>
</li>
<li>
<ins class="diff-new">a
</ins><a class="tref internalDFN" title="language_map" href="#dfn-language_map"><ins class="diff-new">
language
map
</ins></a></li></ul></section><section id="grammar-node-reference"><h3><span class="secno"><ins class="diff-new">
A.2
</ins></span><ins class="diff-new">
Node
Reference
</ins></h3><p>
A
<a class="tref internalDFN" title="json_object" href="#dfn-json_object">
JSON
object
</a>
containing
<del class="diff-old">a
</del>
<ins class="diff-chg">only
the
</ins>
<code>
<del class="diff-old">@set
</del>
<ins class="diff-chg">@id
</ins>
</code>
<del class="diff-old">key
must
</del>
<ins class="diff-chg">(or
an
alias
for
</ins><code><ins class="diff-chg">
@id
</ins></code><ins class="diff-chg">
)
is
a
</ins><a class="tref internalDFN" title="node_reference" href="#dfn-node_reference"><ins class="diff-chg">
node
reference
</ins></a><ins class="diff-chg">
and
</ins>
not
<del class="diff-old">have
any
other
keys.
</del>
<ins class="diff-chg">a
</ins><a class="tref internalDFN" title="node_definition" href="#dfn-node_definition"><ins class="diff-chg">
node
definition
</ins></a>.</p><div class="example"><div class="example-title"><span>Example 64</span>: Explicit node reference</div><pre class="example">{<ins class="diff-chg">
  &quot;@context&quot;: ...,
  &quot;@graph&quot;: [
    {
      &quot;@id&quot;: &quot;http://example.org/library&quot;,
      &quot;@type&quot;: &quot;ex:Library&quot;,
</ins>      <span class="diff">&quot;ex:contains&quot;: {&quot;@id&quot;: &quot;http://example.org/library/the-republic&quot;}</span><ins class="diff-chg">
    }, {
      &quot;@id&quot;: &quot;http://example.org/library/the-republic&quot;,
      &quot;@type&quot;: &quot;ex:Book&quot;,
      &quot;dc:creator&quot;: &quot;Plato&quot;,
      &quot;dc:title&quot;: &quot;The Republic&quot;,
</ins>      <span class="diff">&quot;ex:contains&quot;: {&quot;@id&quot;: &quot;http://example.org/library/the-republic#introduction&quot;}</span><ins class="diff-chg">
    }, {
      &quot;@id&quot;: &quot;http://example.org/library/the-republic#introduction&quot;,
      &quot;@type&quot;: &quot;ex:Chapter&quot;,
      &quot;dc:description&quot;: &quot;An introductory chapter on The Republic.&quot;,
      &quot;dc:title&quot;: &quot;The Introduction&quot;
    }
  ]
}
}
</ins></pre></div></section><section id="grammar-language-map"><h3><span class="secno"><ins class="diff-chg">
A.3
</ins></span><ins class="diff-chg">
Language
Map
</ins></h3><p>
A
<del class="diff-old">JSON
object
</del>
<a class="tref internalDFN" title="language_map" href="#dfn-language_map">
<ins class="diff-chg">language
map
</ins>
</a>
<del class="diff-old">containing
</del>
<ins class="diff-chg">may
be
used
as
a
term
value
within
</ins>
a
<a class="tref internalDFN" title="node_definition" href="#dfn-node_definition">
<ins class="diff-new">node
definition
</ins></a><ins class="diff-new">
if
the
term
is
defined
with
</ins>
<code>
<del class="diff-old">@list
</del>
<ins class="diff-chg">@container
</ins>
</code>
<del class="diff-old">key
</del>
<ins class="diff-chg">set
to
</ins><code><ins class="diff-chg">
@language
</ins></code>.</p><p><ins class="diff-chg">
The
keys
of
a
</ins><a class="tref internalDFN" title="language_map" href="#dfn-language_map"><ins class="diff-chg">
language
map
</ins></a><em class="rfc2119" title="must">
must
<del class="diff-old">not
</del>
</em>
<del class="diff-old">have
</del>
<ins class="diff-chg">be
a
[
</ins><cite><a class="bibref" href="#bib-BCP47"><ins class="diff-chg">
BCP47
</ins></a></cite><ins class="diff-chg">
]
string
with
an
associated
value
that
is
</ins>
any
<del class="diff-old">other
keys.
</del>
<ins class="diff-chg">of
the
following
types:
</ins></p><ul><li><a class="tref internalDFN" title="string" href="#dfn-string"><ins class="diff-chg">
string
</ins></a>,
</li>
<li>
<del class="diff-old">The
</del>
<a class="tref internalDFN" title="number" href="#dfn-number">
<ins class="diff-chg">number
</ins></a>,</li><li><a class="tref internalDFN" title="true" href="#dfn-true"><ins class="diff-chg">
true
</ins></a>,</li><li><a class="tref internalDFN" title="false" href="#dfn-false"><ins class="diff-chg">
false
</ins></a>,</li><li><a class="tref internalDFN" title="null" href="#dfn-null"><ins class="diff-chg">
null
</ins></a>,</li><li><a class="tref internalDFN" title="node_reference" href="#dfn-node_reference"><ins class="diff-chg">
node
reference
</ins></a>,</li><li><a class="tref internalDFN" title="node_definition" href="#dfn-node_definition"><ins class="diff-chg">
node
definition
</ins></a>,</li><li><a class="tref internalDFN" title="typed_value" href="#dfn-typed_value"><ins class="diff-chg">
typed
</ins>
value
<del class="diff-old">of
an
</del>
</a>,
</li>
<li>
<a class="tref internalDFN" title="language-tagged_string" href="#dfn-language-tagged_string">
<ins class="diff-chg">language-tagged
string
</ins></a>,</li><li>
<code>
@set
</code>
or
<code>
@list
</code>
<del class="diff-old">key
can
be
a
string,
a
number,
a
JSON
object
,
</del>
<ins class="diff-chg">definition
(see
</ins><a href="#sets-and-lists" class="sec-ref"><span class="secno"><ins class="diff-chg">
4.9
</ins></span><span class="sec-title"><ins class="diff-chg">
Sets
and
Lists
</ins></span></a><ins class="diff-chg">
),
</ins>
or
</li>
<li>
an
<a class="tref internalDFN" title="array" href="#dfn-array">
array
</a>
<del class="diff-old">containing
a
combination
</del>
<ins class="diff-chg">zero
or
more
</ins>
of
<del class="diff-old">the
allowed
values.
</del>
<ins class="diff-chg">these
</ins>
</li>
<del class="diff-old">For
each
</del>
</ul>
<p class="issue resolved" data-number="133">
<ins class="diff-chg">We
had
also
discussed
values
other
than
strings,
such
as
those
that
might
represent
a
more
reified
version
of
a
value
with
other
properties,
such
as
is
described
using
</ins><a href="http://www.w3.org/TR/skos-reference/skos-xl.html"><ins class="diff-chg">
SKOS-XL
</ins></a>.</p><div class="example"><div class="example-title"><span>Example 65</span>: Language map expressing a property in three languages</div><pre class="example">{<ins class="diff-chg">
  &quot;@context&quot;:
  {
    &quot;title&quot;:
    {
      &quot;@id&quot;: &quot;http://purl.org/dc/terms/title&quot;
</ins>      <span class="diff">&quot;@container&quot;: &quot;@language&quot;</span><ins class="diff-chg">
    }
  },
...
  &quot;title&quot;:
</ins>  <span class="diff">{<ins class="diff-chg">
    &quot;en&quot;: &quot;JSON-LD Syntax&quot;,
    &quot;ru&quot;: &quot;JSON-LD Синтаксис&quot;,
    &quot;ja&quot;: &quot;JSON-LDの構文&quot;
  }</span>
...
}
</ins></pre></div></section><section id="grammar-expanded-values"><h3><span class="secno"><ins class="diff-chg">
A.4
</ins></span><ins class="diff-chg">
Expanded
Values
</ins></h3><p><ins class="diff-chg">
An
</ins><dfn title="expanded_value" id="dfn-expanded_value"><ins class="diff-chg">
expanded
value
</ins></dfn><ins class="diff-chg">
is
a
</ins>
<a class="tref internalDFN" title="json_object" href="#dfn-json_object">
JSON
object
</a>
<del class="diff-old">that
contains
a
</del>
<ins class="diff-chg">containing
the
</ins>
<code>
@value
</code>
<del class="diff-old">key:
</del>
<ins class="diff-chg">key,
or
an
alias
for
the
</ins><code><ins class="diff-chg">
@value
</ins></code><ins class="diff-chg">
value
key.
</ins>
It
<em class="rfc2119" title="may">
may
</em>
<del class="diff-old">have
a
</del>
<ins class="diff-chg">also
contain
the
</ins>
<code>
<del class="diff-old">@language
</del>
<ins class="diff-chg">@type
</ins>
</code>
or
<code>
<del class="diff-old">@type
</del>
<ins class="diff-chg">@language
</ins>
</code>
<del class="diff-old">property
and
</del>
<ins class="diff-chg">keys,
or
their
respective
keyword
aliases.
An
</ins><a class="tref internalDFN" title="expanded_value" href="#dfn-expanded_value"><ins class="diff-chg">
expanded
value
</ins></a>
<em class="rfc2119" title="must not">
must
not
</em>
<del class="diff-old">have
any
</del>
<ins class="diff-chg">contain
keys
</ins>
other
<del class="diff-old">properties.
It
</del>
<ins class="diff-chg">than
</ins><code><ins class="diff-chg">
@value
</ins></code>,<code><ins class="diff-chg">
@language
</ins></code>,<ins class="diff-chg">
and
</ins><code><ins class="diff-chg">
@type
</ins></code>.<ins class="diff-chg">
An
</ins><a class="tref internalDFN" title="expanded_value" href="#dfn-expanded_value"><ins class="diff-chg">
expanded
value
</ins></a>
<em class="rfc2119" title="must not">
must
not
</em>
contain
both
the
<code>
@language
</code>
and
<code>
@type
</code>
<del class="diff-old">keys
at
the
same
time.
</del>
<ins class="diff-chg">keys.
</ins></p><p>
The
value
of
the
<code>
@value
</code>
<del class="diff-old">key
</del>
<ins class="diff-chg">key,
or
its
alias,
</ins>
<em class="rfc2119" title="must">
must
</em>
be
<ins class="diff-new">either
</ins>
a
<a class="tref internalDFN" title="string" href="#dfn-string">
string
</a>,
<a class="tref internalDFN" title="number" href="#dfn-number">
<ins class="diff-new">number
</ins></a>,<a class="tref internalDFN" title="true" href="#dfn-true"><ins class="diff-new">
true
</ins></a>,
or
<a class="tref internalDFN" title="false" href="#dfn-false">
<ins class="diff-new">false
</ins></a>.</p><p><ins class="diff-new">
If
an
</ins><a class="tref internalDFN" title="expanded_value" href="#dfn-expanded_value"><ins class="diff-new">
expanded
value
</ins></a><ins class="diff-new">
contains
</ins>
a
<del class="diff-old">number.
</del>
<code>
<ins class="diff-chg">@language
</ins></code><ins class="diff-chg">
key,
it
</ins><em class="rfc2119" title="must not"><ins class="diff-chg">
must
not
</ins></em><ins class="diff-chg">
contain
any
other
key
except
</ins><code><ins class="diff-chg">
@value
</ins></code>.
The
value
of
the
<code>
@language
</code>
key
<em class="rfc2119" title="must">
must
</em>
<del class="diff-old">be
null
or
a
string
</del>
<ins class="diff-chg">have
the
lexical
form
described
</ins>
in
[
<cite>
<a class="bibref" href="#bib-BCP47">
BCP47
</a>
</cite>
<del class="diff-old">]
format.
</del>
<ins class="diff-chg">],
or
be
</ins><a class="tref internalDFN" title="null" href="#dfn-null"><ins class="diff-chg">
null
</ins></a>.</p><p><ins class="diff-chg">
If
an
</ins><a class="tref internalDFN" title="expanded_value" href="#dfn-expanded_value"><ins class="diff-chg">
expanded
value
</ins></a><ins class="diff-chg">
contains
a
</ins><code><ins class="diff-chg">
@type
</ins></code><ins class="diff-chg">
key,
it
</ins><em class="rfc2119" title="must not"><ins class="diff-chg">
must
not
</ins></em><ins class="diff-chg">
contain
any
other
key
except
</ins><code><ins class="diff-chg">
@value
</ins></code>.
The
value
of
<code>
@type
</code>
<em class="rfc2119" title="must">
must
</em>
be
<del class="diff-old">null
,
</del>
a
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>,
<del class="diff-old">a
</del>
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
compact
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>,
<del class="diff-old">an
</del>
<a class="tref internalDFN" title="absolute_iri" href="#dfn-absolute_iri">
<ins class="diff-chg">absolute
</ins>
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>,
<ins class="diff-new">or
</ins><code><ins class="diff-new">
null
</ins></code>.</p><p><ins class="diff-new">
See
</ins><a href="#typed-values" class="sec-ref"><span class="secno"><ins class="diff-new">
4.2
</ins></span><span class="sec-title"><ins class="diff-new">
Typed
Values
</ins></span></a><ins class="diff-new">
and
</ins><a href="#language-tagged-strings" class="sec-ref"><span class="secno"><ins class="diff-new">
4.3
</ins></span><span class="sec-title"><ins class="diff-new">
Language-tagged
Strings
</ins></span></a><ins class="diff-new">
for
a
further
discussion
of
</ins><a class="tref internalDFN" title="expanded_value" href="#dfn-expanded_value"><ins class="diff-new">
expanded
values
</ins></a>.</p></section><section id="grammar-set-list"><h3><span class="secno"><ins class="diff-new">
A.5
</ins></span><ins class="diff-new">
List
and
Set
Values
</ins></h3><p><ins class="diff-new">
A
</ins><dfn title="list" id="dfn-list"><ins class="diff-new">
list
</ins></dfn><ins class="diff-new">
is
</ins>
a
<a class="tref internalDFN" title="json_object" href="#dfn-json_object">
JSON
object
</a>
<ins class="diff-new">having
only
the
</ins><code><ins class="diff-new">
@list
</ins></code><a class="tref internalDFN" title="keyword" href="#dfn-keyword"><ins class="diff-new">
keyword
</ins></a>.<ins class="diff-new">
Its
value
</ins><em class="rfc2119" title="must"><ins class="diff-new">
must
</ins></em><ins class="diff-new">
be
an
</ins><a class="tref internalDFN" title="array" href="#dfn-array"><ins class="diff-new">
array
</ins></a><ins class="diff-new">
of
any
of
the
following:
</ins></p><ul><li><a class="tref internalDFN" title="string" href="#dfn-string"><ins class="diff-new">
string
</ins></a>,</li><li><a class="tref internalDFN" title="node_reference" href="#dfn-node_reference"><ins class="diff-new">
node
reference
</ins></a>,</li><li><a class="tref internalDFN" title="node_definition" href="#dfn-node_definition"><ins class="diff-new">
node
definition
</ins></a>,</li><li><a class="tref internalDFN" title="typed_value" href="#dfn-typed_value"><ins class="diff-new">
typed
value
</ins>
</a>,
or
</li>
<li>
<a class="tref internalDFN" title="language-tagged_string" href="#dfn-language-tagged_string">
<ins class="diff-new">language-tagged
string
</ins></a>.</li></ul><p><ins class="diff-new">
A
</ins><dfn title="set" id="dfn-set"><ins class="diff-new">
set
</ins></dfn><ins class="diff-new">
is
a
</ins><a class="tref internalDFN" title="json_object" href="#dfn-json_object"><ins class="diff-new">
JSON
object
</ins></a><ins class="diff-new">
having
only
the
</ins><code><ins class="diff-new">
@set
</ins></code><a class="tref internalDFN" title="keyword" href="#dfn-keyword"><ins class="diff-new">
keyword
</ins></a>.<ins class="diff-new">
Its
value
</ins><em class="rfc2119" title="must"><ins class="diff-new">
must
</ins></em><ins class="diff-new">
be
</ins>
an
<a class="tref internalDFN" title="array" href="#dfn-array">
array
</a>
<del class="diff-old">containing
a
combination
</del>
<ins class="diff-chg">of
any
</ins>
of
the
<del class="diff-old">allowed
values.
</del>
<ins class="diff-chg">following:
</ins></p><ul><li><a class="tref internalDFN" title="string" href="#dfn-string"><ins class="diff-chg">
string
</ins></a>,
</li>
<li>
<a class="tref internalDFN" title="node_reference" href="#dfn-node_reference">
<ins class="diff-chg">node
reference
</ins></a>,
</li>
<li>
<del class="diff-old">In
</del>
<a class="tref internalDFN" title="node_definition" href="#dfn-node_definition">
<ins class="diff-chg">node
definition
</ins></a>,</li><li><a class="tref internalDFN" title="typed_value" href="#dfn-typed_value"><ins class="diff-chg">
typed
value
</ins></a>,</li><li><a class="tref internalDFN" title="language-tagged_string" href="#dfn-language-tagged_string"><ins class="diff-chg">
language-tagged
string
</ins></a>,</li><li><code><ins class="diff-chg">
@set
</ins></code><ins class="diff-chg">
or
</ins><code><ins class="diff-chg">
@list
</ins></code><ins class="diff-chg">
definition
(see
</ins><a href="#sets-and-lists" class="sec-ref"><span class="secno"><ins class="diff-chg">
4.9
</ins></span><span class="sec-title"><ins class="diff-chg">
Sets
and
Lists
</ins></span></a><ins class="diff-chg">
),
or
</ins></li><li><ins class="diff-chg">
an
</ins><a class="tref internalDFN" title="array" href="#dfn-array"><ins class="diff-chg">
array
</ins></a><ins class="diff-chg">
zero
or
more
of
these.
</ins></li></ul><p><ins class="diff-chg">
See
</ins><a href="#sets-and-lists" class="sec-ref"><span class="secno"><ins class="diff-chg">
4.9
</ins></span><span class="sec-title"><ins class="diff-chg">
Sets
and
Lists
</ins></span></a><ins class="diff-chg">
for
a
further
discussion
of
List
and
Set
Values.
</ins></p></section><section id="grammar-context"><h3><span class="secno"><ins class="diff-chg">
A.6
</ins></span><ins class="diff-chg">
Context
Definition
</ins></h3><p><ins class="diff-chg">
A
</ins><dfn title="context_definition" id="dfn-context_definition"><ins class="diff-chg">
context
definition
</ins></dfn><ins class="diff-chg">
is
a
</ins><a class="tref internalDFN" title="json_object" href="#dfn-json_object"><ins class="diff-chg">
JSON
object
</ins></a><ins class="diff-chg">
containing
one
or
more
key-value
pairs.
Keys
are
non-keyword
</ins><a class="tref internalDFN" title="string" href="#dfn-string"><ins class="diff-chg">
strings
</ins></a><ins class="diff-chg">
or
</ins>
the
<del class="diff-old">body
</del>
<code>
<ins class="diff-chg">@language
</ins></code><ins class="diff-chg">
or
</ins><code><ins class="diff-chg">
@vocab
</ins></code><a class="tref internalDFN" title="keyword" href="#dfn-keyword"><ins class="diff-chg">
keywords
</ins></a>.<ins class="diff-chg">
A
</ins><a class="tref internalDFN" title="context_definition" href="#dfn-context_definition"><ins class="diff-chg">
context
definition
</ins></a><em class="rfc2119" title="should not"><ins class="diff-chg">
should
not
</ins></em><ins class="diff-chg">
contain
any
keys
having
the
lexical
form
</ins>
of
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
<ins class="diff-new">keyword
</ins></a><ins class="diff-new">
other
than
</ins><code><ins class="diff-new">
@language
</ins></code><ins class="diff-new">
or
</ins><code><ins class="diff-new">
@vocab
</ins></code>.</p><p><ins class="diff-new">
If
the
</ins><a class="tref internalDFN" title="context_definition" href="#dfn-context_definition"><ins class="diff-new">
context
definition
</ins></a><ins class="diff-new">
has
</ins>
a
<del class="diff-old">JSON-LD
document,
</del>
<code>
<ins class="diff-chg">@language
</ins></code><ins class="diff-chg">
key,
</ins>
the
value
<del class="diff-old">of
</del>
<em class="rfc2119" title="must">
<ins class="diff-chg">must
</ins></em><ins class="diff-chg">
have
the
lexical
form
described
in
[
</ins><cite><a class="bibref" href="#bib-BCP47"><ins class="diff-chg">
BCP47
</ins></a></cite><ins class="diff-chg">
]
or
be
</ins><a class="tref internalDFN" title="null" href="#dfn-null"><ins class="diff-chg">
null
</ins></a>.</p><p><ins class="diff-chg">
If
the
</ins><a class="tref internalDFN" title="context_definition" href="#dfn-context_definition"><ins class="diff-chg">
context
definition
</ins></a><ins class="diff-chg">
has
a
</ins>
<code>
<del class="diff-old">@type
</del>
<ins class="diff-chg">@vocab
</ins>
</code>
<ins class="diff-chg">key,
the
value
</ins><em class="rfc2119" title="must"><ins class="diff-chg">
must
</ins></em><ins class="diff-chg">
have
the
lexical
form
of
</ins><a class="tref internalDFN" title="absolute_iri" href="#dfn-absolute_iri"><ins class="diff-chg">
absolute
</ins><abbr title="Internationalized Resource Identifier"><ins class="diff-chg">
IRI
</ins></abbr></a><ins class="diff-chg">
or
be
</ins><a class="tref internalDFN" title="null" href="#dfn-null"><ins class="diff-chg">
null
</ins></a>.</p><p><ins class="diff-chg">
Other
keys
are
</ins><a class="tref internalDFN" title="term" href="#dfn-term"><ins class="diff-chg">
term
</ins></a><ins class="diff-chg">
definitions.
Their
values
</ins><em class="rfc2119" title="must">
must
<del class="diff-old">not
</del>
</em>
be
<ins class="diff-new">either
a
</ins><a class="tref internalDFN" title="string" href="#dfn-string"><ins class="diff-new">
string
</ins></a>,<ins class="diff-new">
or
a
</ins><a class="tref internalDFN" title="json_object" href="#dfn-json_object"><ins class="diff-new">
JSON
object
</ins></a><ins class="diff-new">
having
the
form
of
an
</ins><a class="tref internalDFN" title="expanded_term_definition" href="#dfn-expanded_term_definition"><ins class="diff-new">
expanded
term
definition
</ins></a><ins class="diff-new">
(see
</ins><a href="#expanded-term-definition" class="sec-ref"><span class="secno"><ins class="diff-new">
4.5
</ins></span><span class="sec-title"><ins class="diff-new">
Expanded
Term
Definition
</ins></span></a><ins class="diff-new">
).
</ins></p><p><ins class="diff-new">
An
</ins><dfn title="expanded_term_definition" id="dfn-expanded_term_definition"><ins class="diff-new">
expanded
term
definition
</ins></dfn><ins class="diff-new">
is
composed
of
zero
or
more
keys
from
</ins>
<code>
@id
</code>,
<code>
<ins class="diff-new">@type
</ins></code>,<code><ins class="diff-new">
@language
</ins></code><ins class="diff-new">
or
</ins><code><ins class="diff-new">
@container
</ins>
</code>.
<del class="diff-old">This
</del>
<ins class="diff-chg">An
</ins><a class="tref internalDFN" title="expanded_term_definition" href="#dfn-expanded_term_definition"><ins class="diff-chg">
expanded
term
definition
</ins></a><em class="rfc2119" title="should not"><ins class="diff-chg">
should
not
</ins></em><ins class="diff-chg">
contain
any
other
keys.
All
values
associated
with
</ins><code><ins class="diff-chg">
@id
</ins></code><em class="rfc2119" title="must"><ins class="diff-chg">
must
</ins></em><ins class="diff-chg">
expand
to
an
</ins><a class="tref internalDFN" title="absolute_iri" href="#dfn-absolute_iri"><ins class="diff-chg">
absolute
</ins><abbr title="Internationalized Resource Identifier"><ins class="diff-chg">
IRI
</ins></abbr></a>.</p><p><ins class="diff-chg">
If
the
</ins><a class="tref internalDFN" title="term" href="#dfn-term"><ins class="diff-chg">
term
</ins></a><ins class="diff-chg">
definition
</ins>
is
<ins class="diff-new">not
a
</ins><a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri"><ins class="diff-new">
compact
</ins><abbr title="Internationalized Resource Identifier"><ins class="diff-new">
IRI
</ins></abbr></a><ins class="diff-new">
or
</ins><a class="tref internalDFN" title="absolute_iri" href="#dfn-absolute_iri"><ins class="diff-new">
absolute
</ins><abbr title="Internationalized Resource Identifier"><ins class="diff-new">
IRI
</ins></abbr></a>,<ins class="diff-new">
the
</ins><a class="tref internalDFN" title="expanded_term_definition" href="#dfn-expanded_term_definition"><ins class="diff-new">
expanded
term
definition
</ins></a><em class="rfc2119" title="must"><ins class="diff-new">
must
</ins></em><ins class="diff-new">
include
the
</ins><code><ins class="diff-new">
@id
</ins></code><ins class="diff-new">
key.
</ins></p><p><ins class="diff-new">
If
the
</ins><a class="tref internalDFN" title="expanded_term_definition" href="#dfn-expanded_term_definition"><ins class="diff-new">
expanded
term
definition
</ins></a><ins class="diff-new">
contains
the
</ins><code><ins class="diff-new">
@id
</ins></code><a class="tref internalDFN" title="keyword" href="#dfn-keyword"><ins class="diff-new">
keyword
</ins></a>,<ins class="diff-new">
it
</ins><em class="rfc2119" title="must"><ins class="diff-new">
must
</ins></em><ins class="diff-new">
be
a
</ins><a class="tref internalDFN" title="string" href="#dfn-string"><ins class="diff-new">
string
</ins></a><ins class="diff-new">
having
the
lexical
form
of
</ins><a class="tref internalDFN" title="iri" href="#dfn-iri"><abbr title="Internationalized Resource Identifier"><ins class="diff-new">
IRI
</ins></abbr></a>,<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri"><ins class="diff-new">
compact
</ins><abbr title="Internationalized Resource Identifier"><ins class="diff-new">
IRI
</ins></abbr></a>,<ins class="diff-new">
a
</ins><a class="tref internalDFN" title="term" href="#dfn-term"><ins class="diff-new">
term
</ins></a><ins class="diff-new">
defined
</ins>
in
<del class="diff-old">contrast
to
</del>
the
<del class="diff-old">use
</del>
<ins class="diff-chg">defining
</ins><a class="tref internalDFN" title="context_definition" href="#dfn-context_definition"><ins class="diff-chg">
context
definition
</ins></a><ins class="diff-chg">
or
the
</ins><a class="tref internalDFN" title="active_context" href="#dfn-active_context"><ins class="diff-chg">
active
context
</ins></a>,<ins class="diff-chg">
or
an
</ins><a class="tref internalDFN" title="array" href="#dfn-array"><ins class="diff-chg">
array
</ins></a><ins class="diff-chg">
composed
of
any
</ins>
of
<ins class="diff-new">the
previous
allowed
values.
</ins></p><p><ins class="diff-new">
If
the
</ins><a class="tref internalDFN" title="expanded_term_definition" href="#dfn-expanded_term_definition"><ins class="diff-new">
expanded
term
definition
</ins></a><ins class="diff-new">
contains
the
</ins>
<code>
@type
</code>
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
<ins class="diff-new">keyword
</ins></a>,<ins class="diff-new">
it
</ins><em class="rfc2119" title="must"><ins class="diff-new">
must
</ins></em><ins class="diff-new">
be
a
</ins><a class="tref internalDFN" title="string" href="#dfn-string"><ins class="diff-new">
string
</ins></a><ins class="diff-new">
having
the
lexical
form
of
</ins><a class="tref internalDFN" title="absolute_iri" href="#dfn-absolute_iri"><ins class="diff-new">
absolute
</ins><abbr title="Internationalized Resource Identifier"><ins class="diff-new">
IRI
</ins></abbr></a>,<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri"><ins class="diff-new">
compact
</ins><abbr title="Internationalized Resource Identifier"><ins class="diff-new">
IRI
</ins></abbr></a>,<ins class="diff-new">
or
a
</ins><a class="tref internalDFN" title="term" href="#dfn-term"><ins class="diff-new">
term
</ins></a><ins class="diff-new">
defined
in
the
defining
</ins><a class="tref internalDFN" title="context_definition" href="#dfn-context_definition"><ins class="diff-new">
context
definition
</ins></a><ins class="diff-new">
or
the
</ins><a class="tref internalDFN" title="active_context" href="#dfn-active_context"><ins class="diff-new">
active
context
</ins></a>.</p><p><ins class="diff-new">
If
the
</ins><a class="tref internalDFN" title="expanded_term_definition" href="#dfn-expanded_term_definition"><ins class="diff-new">
expanded
term
definition
</ins></a><ins class="diff-new">
contains
the
</ins><code><ins class="diff-new">
@language
</ins></code><a class="tref internalDFN" title="keyword" href="#dfn-keyword"><ins class="diff-new">
keyword
</ins></a>,<ins class="diff-new">
the
value
</ins><em class="rfc2119" title="must"><ins class="diff-new">
must
</ins></em><ins class="diff-new">
have
the
lexical
form
described
</ins>
in
<ins class="diff-new">[
</ins><cite><a class="bibref" href="#bib-BCP47"><ins class="diff-new">
BCP47
</ins></a></cite><ins class="diff-new">
]
or
be
</ins><a class="tref internalDFN" title="null" href="#dfn-null"><ins class="diff-new">
null
</ins></a>.</p><p><ins class="diff-new">
If
the
</ins><a class="tref internalDFN" title="expanded_term_definition" href="#dfn-expanded_term_definition"><ins class="diff-new">
expanded
term
definition
</ins></a><ins class="diff-new">
contains
</ins>
the
<code>
<del class="diff-old">@context
</del>
<ins class="diff-chg">@container
</ins></code><a class="tref internalDFN" title="keyword" href="#dfn-keyword"><ins class="diff-chg">
keyword
</ins></a>,<ins class="diff-chg">
the
value
</ins><em class="rfc2119" title="must"><ins class="diff-chg">
must
</ins></em><ins class="diff-chg">
be
either
</ins><code><ins class="diff-chg">
@list
</ins>
</code>,
<del class="diff-old">where
this
</del>
<code>
<ins class="diff-chg">@set
</ins></code>,<code><ins class="diff-chg">
@language
</ins></code>,<ins class="diff-chg">
or
be
</ins><a class="tref internalDFN" title="null" href="#dfn-null"><ins class="diff-chg">
null
</ins></a>.<ins class="diff-chg">
If
the
value
</ins>
is
<del class="diff-old">allowed.
</del>
<code>
<ins class="diff-chg">@language
</ins></code>,<ins class="diff-chg">
when
the
</ins><a class="tref internalDFN" title="term" href="#dfn-term"><ins class="diff-chg">
term
</ins></a><ins class="diff-chg">
is
used
outside
of
the
</ins><code><ins class="diff-chg">
@context
</ins></code>,<ins class="diff-chg">
the
associated
value
</ins><em class="rfc2119" title="must"><ins class="diff-chg">
must
</ins></em><ins class="diff-chg">
be
a
</ins><a class="tref internalDFN" title="json_object" href="#dfn-json_object"><ins class="diff-chg">
JSON
object
</ins></a><ins class="diff-chg">
whose
keys
are
</ins><a class="tref internalDFN" title="string" href="#dfn-string"><ins class="diff-chg">
string
</ins></a><ins class="diff-chg">
s
that
are
[
</ins><cite><a class="bibref" href="#bib-BCP47"><ins class="diff-chg">
BCP47
</ins></a></cite><ins class="diff-chg">
]
language
identifiers.
The
values
associated
with
each
[
</ins><cite><a class="bibref" href="#bib-BCP47"><ins class="diff-chg">
BCP47
</ins></a></cite><ins class="diff-chg">
]
language
string
</ins><em class="rfc2119" title="must"><ins class="diff-chg">
must
</ins></em><ins class="diff-chg">
be
a
</ins><a class="tref internalDFN" title="string" href="#dfn-string"><ins class="diff-chg">
string
</ins></a><ins class="diff-chg">
or
an
</ins><a class="tref internalDFN" title="array" href="#dfn-array"><ins class="diff-chg">
array
</ins></a><ins class="diff-chg">
of
</ins><a class="tref internalDFN" title="string" href="#dfn-string"><ins class="diff-chg">
string
</ins></a><ins class="diff-chg">
s.
</ins></p><p><ins class="diff-chg">
See
</ins><a href="#the-context" class="sec-ref"><span class="secno"><ins class="diff-chg">
3.5
</ins></span><span class="sec-title"><ins class="diff-chg">
The
Context
</ins></span></a><ins class="diff-chg">
and
</ins><a href="#expanded-term-definition" class="sec-ref"><span class="secno"><ins class="diff-chg">
4.5
</ins></span><span class="sec-title"><ins class="diff-chg">
Expanded
Term
Definition
</ins></span></a><ins class="diff-chg">
for
a
further
discussion
of
contexts.
</ins></p></section><div class="example"><div class="example-title"><span>Example 66</span>: Context definition with simple terms, expanded term definitions and @language</div><pre class="example">{<ins class="diff-chg">
  &quot;@language&quot;: &quot;en&quot;,
  &quot;xsd&quot;: &quot;http://www.w3.org/2001/XMLSchema#&quot;,
  &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;,
  &quot;name&quot;: &quot;foaf:name&quot;,
  &quot;depiction&quot;: {&quot;@id&quot;: &quot;foaf:depiction&quot;, &quot;@type&quot;: &quot;@id&quot;},
  &quot;modified&quot;: {&quot;@id&quot;: &quot;http://purl.org/dc/terms/modified&quot;, &quot;@type&quot;: &quot;xsd:dateTime&quot;},
  &quot;homepage&quot;: {&quot;@id&quot;: &quot;foaf:homepage&quot;, &quot;@type&quot;: &quot;@id&quot;, &quot;@container&quot;: &quot;@list&quot;}
}
</ins></pre>
</div>
</section>
<section class="appendix informative" id="relationship-to-other-linked-data-formats-and-data-models">
<h2>
<span class="secno">
B.
</span>
Relationship
to
<del class="diff-old">other
RDF
</del>
<ins class="diff-chg">Other
Linked
Data
</ins>
Formats
<ins class="diff-new">and
Data
Models
</ins>
</h2>
<p>
<em>
This
section
is
non-normative.
</em>
</p>
<div class="issue">
<div class="issue-title">
<a href="https://github.com/json-ld/json-ld.org/issues/157">
<span>
Issue
<del class="diff-old">6
</del>
<ins class="diff-chg">157
</ins>
</span>
</a>
</div>
<p class="">
The
intent
of
the
Working
Group
and
the
Editors
of
this
specification
is
to
eventually
align
terminology
used
in
this
document
with
the
terminology
used
in
the
RDF
Concepts
document
[
<cite>
<a class="bibref" href="#bib-RDF-CONCEPTS">
RDF-CONCEPTS
</a>
</cite>
]
to
the
extent
to
which
it
makes
sense
to
do
so.
In
general,
if
there
is
an
analogue
to
terminology
used
in
this
document
in
the
RDF
Concepts
document,
the
preference
is
to
use
the
terminology
in
the
RDF
Concepts
document.
</p>
</div>
<p>
JSON-LD
is
a
specification
for
representing
<a class="tref internalDFN" title="linked_data" href="#dfn-linked_data">
Linked
Data
</a>
in
JSON.
A
common
way
of
working
with
Linked
Data
is
through
<dfn title="rdf" id="dfn-rdf">
RDF
</dfn>,
the
Resource
Description
Framework.
RDF
can
be
expressed
using
JSON-LD
by
associating
JSON-LD
concepts
such
as
<code>
@id
</code>
and
<code>
@type
</code>
with
the
equivalent
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
s
in
RDF.
Further
information
about
RDF
may
be
found
in
the
[
<cite>
<a class="bibref" href="#bib-RDF-PRIMER">
RDF-PRIMER
</a>
</cite>
].
</p>
<p>
The
JSON-LD
markup
examples
below
demonstrate
how
JSON-LD
can
be
used
to
express
semantic
data
marked
up
in
other
languages
and
data
models
such
as
RDF,
Turtle,
RDFa,
Microformats,
and
Microdata.
These
sections
are
merely
provided
as
evidence
that
JSON-LD
is
very
flexible
in
what
it
can
express
across
different
<a class="tref internalDFN" title="linked_data" href="#dfn-linked_data">
Linked
Data
</a>
approaches.
Further
information
on
transforming
JSON-LD
into
RDF
are
detailed
in
the
[
<cite>
<a class="bibref" href="#bib-JSON-LD-API">
JSON-LD-API
</a>
</cite>
].
</p>
<section id="rdf">
<h3>
<span class="secno">
B.1
</span>
RDF
</h3>
<p>
<em>
This
section
is
non-normative.
</em>
</p>
<p>
The
RDF
data
model,
as
outlined
in
[
<cite>
<a class="bibref" href="#bib-RDF-CONCEPTS">
RDF-CONCEPTS
</a>
</cite>
],
is
an
abstract
syntax
for
representing
a
directed
graph
of
information.
JSON-LD
is
capable
of
serializing
any
RDF
graph,
and
performing
full
RDF
to
JSON-LD
to
RDF
round-tripping.
A
complete
description
of
how
JSON-LD
maps
to
RDF
and
algorithms
detailing
how
one
can
convert
from
RDF
to
JSON-LD
and
from
JSON-LD
to
RDF
are
included
in
the
JSON-LD
API
[
<cite>
<a class="bibref" href="#bib-JSON-LD-API">
JSON-LD-API
</a>
</cite>
]
specification.
</p>
<p>
<ins class="diff-chg">JSON-LD
allows
properties
to
be
BNodes,
while
RDF
does
not.
Expressing
properties
as
BNodes
in
JSON-LD
only
becomes
an
issue
(and
could
raise
an
exception)
when
it
is
transformed
to
RDF.
</ins></p><p><ins class="diff-chg">
Note
that
the
JSON-LD
data
model
is
silent
on
the
topic
of
</ins><a class="tref internalDFN" title="unlabeled_node" href="#dfn-unlabeled_node"><ins class="diff-chg">
unlabeled
nodes
</ins></a>.<ins class="diff-chg">
Nevertheless,
this
specification
allows
for
the
expression
of
</ins><a class="tref internalDFN" title="unlabeled_node" href="#dfn-unlabeled_node"><ins class="diff-chg">
unlabeled
nodes
</ins></a>,<ins class="diff-chg">
as
most
graph-based
data
sets
on
the
Web
contain
a
number
of
associated
nodes
that
are
not
named
and
thus
are
not
directly
de-referenceable.
</ins></p><section id="turtle"><h4>
<span class="secno">
<del class="diff-old">B.2
</del>
<ins class="diff-chg">B.1.1
</ins>
</span>
Turtle
</h4>
<p>
<em>
<ins class="diff-chg">This
section
is
non-normative.
</ins></em></p>
<p>
The
following
are
examples
of
converting
<a class="tref internalDFN" title="rdf" href="#dfn-rdf">
RDF
</a>
expressed
in
[
<cite>
<a class="bibref" href="#bib-TURTLE-TR">
TURTLE-TR
</a>
</cite>
]
into
JSON-LD.
</p>
<section id="prefix-definitions">
<h5>
<span class="secno">
<del class="diff-old">B.2.1
</del>
<ins class="diff-chg">B.1.1.1
</ins>
</span>
Prefix
definitions
</h5>
<p>
<em>
This
section
is
non-normative.
</em>
</p>
<p>
The
JSON-LD
context
has
direct
equivalents
for
the
Turtle
<code>
@prefix
</code>
declaration:
</p>
<del class="diff-old">@prefix foaf: &lt;http://xmlns.com/foaf/0.1/&gt; .
</del>
<div class="example"><div class="example-title"><span>Example 67</span></div><pre class="example">@prefix foaf: &lt;http://xmlns.com/foaf/0.1/&gt; .
&lt;http://manu.sporny.org/i/public&gt; a foaf:Person;
  foaf:name &quot;Manu Sporny&quot;;
foaf:homepage
&lt;http://manu.sporny.org/&gt;
.
</pre>
</div>
<del class="diff-old">{
</del>
<div class="example"><div class="example-title"><span>Example 68</span></div><pre class="example">{
  &quot;@context&quot;:
  {
    &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;
  },
  &quot;@id&quot;: &quot;http://manu.sporny.org/i/public&quot;,
  &quot;@type&quot;: &quot;foaf:Person&quot;,
  &quot;foaf:name&quot;: &quot;Manu Sporny&quot;,
  &quot;foaf:homepage&quot;: { &quot;@id&quot;: &quot;http://manu.sporny.org/&quot; }
}
</pre>
</div>
<div class="note">
<div class="note-title">
<span>
Note
</span>
</div>
<p class="">
JSON-LD
has
no
equivalent
for
the
Turtle
<code>
@base
</code>
declaration.
<del class="diff-old">Instead,
authors
may
use
a
prefix
definition
to
resolve
relative
IRI
s:
</del>
</p>
<del class="diff-old">{
  &quot;@context&quot;:
  {
    
    &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;
  },
  &quot;@id&quot;: ,
  &quot;@type&quot;: &quot;foaf:Person&quot;,
  &quot;foaf:name&quot;: &quot;Manu Sporny&quot;,
  &quot;foaf:homepage&quot;: { &quot;@id&quot;: }
}
</del>
</div>
</section>
<section id="embedding-1">
<h5>
<span class="secno">
<del class="diff-old">B.2.2
</del>
<ins class="diff-chg">B.1.1.2
</ins>
</span>
Embedding
</h5>
<p>
Both
Turtle
and
JSON-LD
allow
<del class="diff-old">embedding
of
objects,
</del>
<ins class="diff-chg">embedding,
</ins>
although
Turtle
only
allows
embedding
of
<del class="diff-old">objects
which
use
</del>
<a class="tref internalDFN" title="unlabeled_node" href="#dfn-unlabeled_node">
unlabeled
<del class="diff-old">node
identifiers.
</del>
<ins class="diff-chg">nodes
</ins></a>.
</p>
<del class="diff-old">@prefix foaf: &lt;http://xmlns.com/foaf/0.1/&gt; .
</del>
</section>
<div class="example"><div class="example-title"><span>Example 69</span></div><pre class="example">@prefix foaf: &lt;http://xmlns.com/foaf/0.1/&gt; .
&lt;http://manu.sporny.org/i/public&gt;
  a foaf:Person;
  foaf:name &quot;Manu Sporny&quot;;
foaf:knows
[
a
foaf:Person;
foaf:name
&quot;Gregg
Kellogg&quot;
]
.
</pre>
</div>
<del class="diff-old">{
</del>
<div class="example"><div class="example-title"><span>Example 70</span></div><pre class="example">{
  &quot;@context&quot;:
  {
    &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;
  },
  &quot;@id&quot;: &quot;http://manu.sporny.org/i/public&quot;,
  &quot;@type&quot;: &quot;foaf:Person&quot;,
  &quot;foaf:name&quot;: &quot;Manu Sporny&quot;,
  &quot;foaf:knows&quot;:
  {
    &quot;@type&quot;: &quot;foaf:Person&quot;,
    &quot;foaf:name&quot;: &quot;Gregg Kellogg&quot;
  }
}
</pre>
</div>
<section id="lists">
<h5>
<span class="secno">
<del class="diff-old">B.2.3
</del>
<ins class="diff-chg">B.1.1.3
</ins>
</span>
Lists
</h5>
<p>
Both
JSON-LD
and
Turtle
can
represent
sequential
lists
of
values.
</p>
<del class="diff-old">@prefix foaf: &lt;http://xmlns.com/foaf/0.1/&gt; .
</del>
<div class="example"><div class="example-title"><span>Example 71</span></div><pre class="example">@prefix foaf: &lt;http://xmlns.com/foaf/0.1/&gt; .
&lt;http://example.org/people#joebob&gt; a foaf:Person;
  foaf:name &quot;Joe Bob&quot;;
foaf:nick
(
&quot;joe&quot;
&quot;bob&quot;
&quot;jaybee&quot;
)
.
</pre>
</div>
<del class="diff-old">{
</del>
<div class="example"><div class="example-title"><span>Example 72</span></div><pre class="example">{
  &quot;@context&quot;:
  {
    &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;
  },
  &quot;@id&quot;: &quot;http://example.org/people#joebob&quot;,
  &quot;@type&quot;: &quot;foaf:Person&quot;,
  &quot;foaf:name&quot;: &quot;Joe Bob&quot;,
  &quot;foaf:nick&quot;:
  {
    &quot;@list&quot;: [ &quot;joe&quot;, &quot;bob&quot;, &quot;jaybee&quot; ]
  }
}
</pre>
</div>
</section>
</section>
<section id="rdfa">
<h4>
<span class="secno">
<del class="diff-old">B.3
</del>
<ins class="diff-chg">B.1.2
</ins>
</span>
RDFa
</h4>
<p>
The
following
example
describes
three
people
with
their
respective
names
and
homepages.
</p>
<del class="diff-old">&gt;
</del>
<div class="example"><div class="example-title"><span>Example 73</span></div><pre class="example">&lt;div <span class="diff">prefix=&quot;foaf: http://xmlns.com/foaf/0.1/&quot;</span>&gt;
   &lt;ul&gt;
      &lt;li <span class="diff">typeof=&quot;foaf:Person&quot;</span>&gt;
        &lt;a <span class="diff">rel=&quot;foaf:homepage&quot; href=&quot;http://example.com/bob/&quot; property=&quot;foaf:name&quot; </span>&gt;Bob&lt;/a&gt;
      &lt;/li&gt;
      &lt;li <span class="diff">typeof=&quot;foaf:Person&quot;</span>&gt;
        &lt;a <span class="diff">rel=&quot;foaf:homepage&quot; href=&quot;http://example.com/eve/&quot; property=&quot;foaf:name&quot; </span>&gt;Eve&lt;/a&gt;
      &lt;/li&gt;
      &lt;li <span class="diff">typeof=&quot;foaf:Person&quot;</span>&gt;
        &lt;a <span class="diff">rel=&quot;foaf:homepage&quot; href=&quot;http://example.com/manu/&quot; property=&quot;foaf:name&quot; </span>&gt;Manu&lt;/a&gt;
      &lt;/li&gt;
   &lt;/ul&gt;
&lt;/div&gt;
</pre>
</div>
<p>
An
example
JSON-LD
implementation
using
a
single
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>
is
described
below.
</p>
<del class="diff-old">{
</del>
<div class="example"><div class="example-title"><span>Example 74</span></div><pre class="example">{
  &quot;@context&quot;:
  {
    &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;
  },
  &quot;@graph&quot;:
  [
    {
      &quot;@type&quot;: &quot;foaf:Person&quot;,
      &quot;foaf:homepage&quot;: &quot;http://example.com/bob/&quot;,
      &quot;foaf:name&quot;: &quot;Bob&quot;
    },
    {
      &quot;@type&quot;: &quot;foaf:Person&quot;,
      &quot;foaf:homepage&quot;: &quot;http://example.com/eve/&quot;,
      &quot;foaf:name&quot;: &quot;Eve&quot;
    },
    {
      &quot;@type&quot;: &quot;foaf:Person&quot;,
      &quot;foaf:homepage&quot;: &quot;http://example.com/manu/&quot;,
      &quot;foaf:name&quot;: &quot;Manu&quot;
    }
  ]
}
</pre>
</div>
</section>
<section id="microformats">
<h4>
<span class="secno">
<del class="diff-old">B.4
</del>
<ins class="diff-chg">B.1.3
</ins>
</span>
Microformats
</h4>
<p>
The
following
example
uses
a
simple
Microformats
hCard
example
to
express
how
the
Microformat
is
represented
in
JSON-LD.
</p>
<del class="diff-old">&lt;div class=&quot;vcard&quot;&gt;
</del>
<div class="example"><div class="example-title"><span>Example 75</span></div><pre class="example">&lt;div class=&quot;vcard&quot;&gt;
 &lt;a class=&quot;url fn&quot; href=&quot;http://tantek.com/&quot;&gt;Tantek Çelik&lt;/a&gt;
&lt;/div&gt;
</pre>
</div>
<p>
The
representation
of
the
hCard
expresses
the
Microformat
terms
in
the
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>
and
uses
them
directly
for
the
<code>
url
</code>
and
<code>
fn
</code>
properties.
Also
note
that
the
Microformat
to
JSON-LD
processor
has
generated
the
proper
URL
type
for
<code>
http://tantek.com/
</code>.
</p>
<del class="diff-old">{
</del>
<div class="example"><div class="example-title"><span>Example 76</span></div><pre class="example">{
  &quot;@context&quot;:
  {
    &quot;vcard&quot;: &quot;http://microformats.org/profile/hcard#vcard&quot;,
    &quot;url&quot;:
    {
      &quot;@id&quot;: &quot;http://microformats.org/profile/hcard#url&quot;,
      &quot;@type&quot;: &quot;@id&quot;
    },
    &quot;fn&quot;: &quot;http://microformats.org/profile/hcard#fn&quot;
  },
  &quot;@type&quot;: &quot;vcard&quot;,
  &quot;url&quot;: &quot;http://tantek.com/&quot;,
  &quot;fn&quot;: &quot;Tantek Çelik&quot;
}
</pre>
</div>
</section>
<section id="microdata">
<h4>
<span class="secno">
<del class="diff-old">B.5
</del>
<ins class="diff-chg">B.1.4
</ins>
</span>
Microdata
</h4>
<p>
The
microdata
example
below
expresses
book
information
as
a
microdata
Work
item.
</p>
<del class="diff-old">&lt;dl itemscope
</del>
<div class="example"><div class="example-title"><span>Example 77</span></div><pre class="example">&lt;dl itemscope
    itemtype=&quot;http://purl.org/vocab/frbr/core#Work&quot;
    itemid=&quot;http://purl.oreilly.com/works/45U8QJGZSQKDH8N&quot;&gt;
 &lt;dt&gt;Title&lt;/dt&gt;
 &lt;dd&gt;&lt;cite itemprop=&quot;http://purl.org/dc/terms/title&quot;&gt;Just a Geek&lt;/cite&gt;&lt;/dd&gt;
 &lt;dt&gt;By&lt;/dt&gt;
 &lt;dd&gt;&lt;span itemprop=&quot;http://purl.org/dc/terms/creator&quot;&gt;Wil Wheaton&lt;/span&gt;&lt;/dd&gt;
 &lt;dt&gt;Format&lt;/dt&gt;
 &lt;dd itemprop=&quot;http://purl.org/vocab/frbr/core#realization&quot;
     itemscope
     itemtype=&quot;http://purl.org/vocab/frbr/core#Expression&quot;
     itemid=&quot;http://purl.oreilly.com/products/9780596007683.BOOK&quot;&gt;
  &lt;link itemprop=&quot;http://purl.org/dc/terms/type&quot; href=&quot;http://purl.oreilly.com/product-types/BOOK&quot;&gt;
  Print
 &lt;/dd&gt;
 &lt;dd itemprop=&quot;http://purl.org/vocab/frbr/core#realization&quot;
     itemscope
     itemtype=&quot;http://purl.org/vocab/frbr/core#Expression&quot;
     itemid=&quot;http://purl.oreilly.com/products/9780596802189.EBOOK&quot;&gt;
  &lt;link itemprop=&quot;http://purl.org/dc/terms/type&quot; href=&quot;http://purl.oreilly.com/product-types/EBOOK&quot;&gt;
  Ebook
 &lt;/dd&gt;
&lt;/dl&gt;
</pre>
</div>
<p>
Note
that
the
JSON-LD
representation
of
the
Microdata
information
stays
true
to
the
desires
of
the
Microdata
community
to
avoid
contexts
and
instead
refer
to
items
by
their
full
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>.
</p>
<del class="diff-old">[
</del>
<div class="example"><div class="example-title"><span>Example 78</span></div><pre class="example">[
  {
    &quot;@id&quot;: &quot;http://purl.oreilly.com/works/45U8QJGZSQKDH8N&quot;,
    &quot;@type&quot;: &quot;http://purl.org/vocab/frbr/core#Work&quot;,
    &quot;http://purl.org/dc/terms/title&quot;: &quot;Just a Geek&quot;,
    &quot;http://purl.org/dc/terms/creator&quot;: &quot;Whil Wheaton&quot;,
    &quot;http://purl.org/vocab/frbr/core#realization&quot;:
    [
      &quot;http://purl.oreilly.com/products/9780596007683.BOOK&quot;,
      &quot;http://purl.oreilly.com/products/9780596802189.EBOOK&quot;
    ]
  },
  {
    &quot;@id&quot;: &quot;http://purl.oreilly.com/products/9780596007683.BOOK&quot;,
    &quot;@type&quot;: &quot;http://purl.org/vocab/frbr/core#Expression&quot;,
    &quot;http://purl.org/dc/terms/type&quot;: &quot;http://purl.oreilly.com/product-types/BOOK&quot;
  },
  {
    &quot;@id&quot;: &quot;http://purl.oreilly.com/products/9780596802189.EBOOK&quot;,
    &quot;@type&quot;: &quot;http://purl.org/vocab/frbr/core#Expression&quot;,
    &quot;http://purl.org/dc/terms/type&quot;: &quot;http://purl.oreilly.com/product-types/EBOOK&quot;
  }
]
</pre>
</div>
</section>
</section>
<section class="appendix informative" id="iana-considerations">
<h3>
<span class="secno">
<del class="diff-old">C.
</del>
<ins class="diff-chg">B.2
</ins>
</span>
IANA
Considerations
</h3>
<p>
<em>
This
section
is
non-normative.
</em>
</p>
<p>
This
section
is
included
merely
for
standards
community
review
and
will
be
submitted
to
the
Internet
Engineering
Steering
Group
if
this
specification
becomes
a
<abbr title="World Wide Web Consortium">
W3C
</abbr>
Recommendation.
</p>
<h3 id="application-ld-json">
application/ld+json
</h3>
<dl>
<dt>
Type
name:
</dt>
<dd>
application
</dd>
<dt>
Subtype
name:
</dt>
<dd>
ld+json
</dd>
<dt>
Required
parameters:
</dt>
<dd>
None
</dd>
<dt>
Optional
parameters:
</dt>
<dd>
<dl>
<dt>
<code>
form
</code>
</dt>
<dd>
Determines
the
serialization
form
for
the
JSON-LD
document.
The
only
valid
value
at
the
moment
is
<code>
expanded
</code>.
If
no
form
is
specified
in
an
HTTP
request
header
to
an
HTTP
server,
the
server
<em class="rfc2119" title="may">
may
</em>
choose
any
form.
If
no
form
is
specified
in
an
HTTP
response,
the
form
<em class="rfc2119" title="must not">
must
not
</em>
be
assumed
to
take
any
particular
form.
</dd>
</dl>
</dd>
<dt>
Encoding
considerations:
</dt>
<dd>
The
same
as
the
<code>
application/json
</code>
MIME
media
type.
</dd>
<dt>
Security
considerations:
</dt>
<dd>
Since
JSON-LD
is
intended
to
be
a
pure
data
exchange
format
for
directed
graphs,
the
serialization
<em class="rfc2119" title="should not">
should
not
</em>
be
passed
through
a
code
execution
mechanism
such
as
JavaScript's
<code>
eval()
</code>
function.
It
is
<em class="rfc2119" title="recommended">
recommended
</em>
that
a
conforming
parser
does
not
attempt
to
directly
evaluate
the
JSON-LD
serialization
and
instead
purely
parse
the
input
into
a
language-native
data
structure.
</dd>
<dt>
Interoperability
considerations:
</dt>
<dd>
Not
Applicable
</dd>
<dt>
Published
specification:
</dt>
<dd>
The
<a href="http://json-ld.org/spec/latest/">
JSON-LD
</a>
specification.
</dd>
<dt>
Applications
that
use
this
media
type:
</dt>
<dd>
Any
programming
environment
that
requires
the
exchange
of
directed
graphs.
Implementations
of
JSON-LD
have
been
created
for
JavaScript,
Python,
Ruby,
PHP
and
C++.
</dd>
<dt>
Additional
information:
</dt>
<dd>
<dl>
<dt>
Magic
number(s):
</dt>
<dd>
Not
Applicable
</dd>
<dt>
File
extension(s):
</dt>
<dd>.jsonld
</dd>
<dt>
Macintosh
file
type
code(s):
</dt>
<dd>
TEXT
</dd>
</dl>
</dd>
<dt>
Person
&amp;
email
address
to
contact
for
further
information:
</dt>
<dd>
Manu
Sporny
&lt;msporny@digitalbazaar.com&gt;
</dd>
<dt>
Intended
usage:
</dt>
<dd>
Common
</dd>
<dt>
Restrictions
on
usage:
</dt>
<dd>
None
</dd>
<dt>
Author(s):
</dt>
<dd>
Manu
Sporny,
Gregg
Kellogg,
Markus
Lanthaler,
Dave
Longley
</dd>
<dt>
Change
controller:
</dt>
<dd>
<abbr title="World Wide Web Consortium">
W3C
</abbr>
</dd>
</dl>
<p>
Fragment
identifiers
used
with
<a href="#application-ld-json">
application/ld+json
</a>
resources
<em class="rfc2119" title="may">
may
</em>
identify
a
node
in
the
<a class="tref internalDFN" title="linked_data_graph" href="#dfn-linked_data_graph">
linked
data
graph
</a>
expressed
in
the
resource.
This
idiom,
which
is
also
used
in
RDF
[
<cite>
<a class="bibref" href="#bib-RDF-CONCEPTS">
RDF-CONCEPTS
</a>
</cite>
],
gives
a
simple
way
to
&quot;mint&quot;
new,
document-local
IRIs
to
label
nodes
and
therefore
contributes
considerably
to
the
expressive
power
of
JSON-LD.
</p>
</section>
<section class="appendix informative" id="acknowledgements">
<h3>
<span class="secno">
<del class="diff-old">D.
</del>
<ins class="diff-chg">B.3
</ins>
</span>
Acknowledgements
</h3>
<p>
<em>
This
section
is
non-normative.
</em>
</p>
<p>
<ins class="diff-new">A
large
amount
of
thanks
goes
out
to
the
JSON-LD
Community
Group
participants
who
worked
through
many
of
the
technical
issues
on
the
mailing
list
and
the
weekly
telecons
-
of
special
mention
are
Niklas
Lindström,
François
Daoust,
and
Zdenko
'Denny'
Vrandečić.
</ins>
The
editors
would
like
to
thank
Mark
Birbeck,
who
provided
a
great
deal
of
the
initial
push
behind
the
JSON-LD
work
via
his
work
on
<del class="diff-old">RDFj,
</del>
<ins class="diff-chg">RDFj.
The
work
of
</ins>
Dave
Lehn
and
Mike
Johnson
<del class="diff-old">who
reviewed,
provided
feedback,
</del>
<ins class="diff-chg">are
appreciated
for
reviewing,
</ins>
and
<del class="diff-old">performed
</del>
<ins class="diff-chg">performing
</ins>
several
implementations
of
the
<del class="diff-old">specification,
and
</del>
<ins class="diff-chg">specification.
</ins>
Ian
<del class="diff-old">Davis,
who
created
</del>
<ins class="diff-chg">Davis
is
thanked
for
this
work
on
</ins>
RDF/JSON.
Thanks
also
to
Nathan
Rixham,
Bradley
P.
Allen,
Kingsley
Idehen,
Glenn
McDonald,
Alexandre
Passant,
Danny
Ayers,
Ted
Thibodeau
Jr.,
Olivier
Grisel,
Josh
Mandel,
Eric
Prud'hommeaux,
David
Wood,
Guus
Schreiber,
Pat
Hayes,
Sandro
Hawke,
and
Richard
Cyganiak
for
their
input
on
the
specification.
</p>
</section>
</section>
<section id="references" class="appendix">
<h2>
<span class="secno">
<del class="diff-old">E.
</del>
<ins class="diff-chg">C.
</ins>
</span>
References
</h2>
<section id="normative-references">
<h3>
<span class="secno">
<del class="diff-old">E.1
</del>
<ins class="diff-chg">C.1
</ins>
</span>
Normative
references
</h3>
<dl class="bibliography">
<dt id="bib-BCP47">
[BCP47]
</dt>
<dd>
A.
Phillips;
M.
Davis.
<a href="http://tools.ietf.org/html/bcp47">
<cite>
Tags
for
Identifying
Languages
</cite>
</a>
September
2009.
IETF
Best
Current
Practice.
URL:
<a href="http://tools.ietf.org/html/bcp47">
http://tools.ietf.org/html/bcp47
</a>
</dd>
<del class="diff-old">[JSON-LD-API]
The
JSON-LD
API
1.0
Manu
Sporny,
Gregg
Kellogg,
Dave
Longley,
Markus
Lanthaler,
Editors.
World
Wide
Web
Consortium
(work
in
progress).
24
May
2012.
Editor's
Draft.
This
edition
of
the
JSON-LD
Syntax
specification
is
http://json-ld.org/spec/ED/json-ld-api/20120524/.
The
latest
edition
of
the
JSON-LD
Syntax
is
available
at
http://json-ld.org/spec/latest/json-ld-api/
</del>
<dt id="bib-RDF-CONCEPTS">
[RDF-CONCEPTS]
</dt>
<dd>
<cite>
<a href="http://www.w3.org/TR/2011/WD-rdf11-concepts-20110830/">
RDF
1.1
Concepts
and
Abstract
Syntax
</a>
</cite>
Richard
Cyganiak,
David
Wood,
Editors.
World
Wide
Web
Consortium
(work
in
progress).
30
May
2012.
Editor's
Draft.
This
edition
of
the
JSON-LD
Syntax
specification
is
http://www.w3.org/TR/2011/WD-rdf11-concepts-20110830/.
The
<a href="http://www.w3.org/TR/rdf11-concepts/">
latest
edition
of
the
JSON-LD
Syntax
</a>
is
available
at
http://www.w3.org/TR/rdf11-concepts/
</dd>
<dt id="bib-RFC3987">
[RFC3987]
</dt>
<dd>
M.
Dürst;
M.
Suignard.
<a href="http://www.ietf.org/rfc/rfc3987.txt">
<cite>
Internationalized
Resource
Identifiers
(IRIs).
</cite>
</a>
January
2005.
Internet
RFC
3987.
URL:
<a href="http://www.ietf.org/rfc/rfc3987.txt">
http://www.ietf.org/rfc/rfc3987.txt
</a>
</dd>
<dt id="bib-RFC4627">
[RFC4627]
</dt>
<dd>
D.
Crockford.
<a href="http://www.ietf.org/rfc/rfc4627.txt">
<cite>
The
application/json
Media
Type
for
JavaScript
Object
Notation
(JSON)
</cite>
</a>
July
2006.
Internet
RFC
4627.
URL:
<a href="http://www.ietf.org/rfc/rfc4627.txt">
http://www.ietf.org/rfc/rfc4627.txt
</a>
</dd>
<dt id="bib-RFC5988">
[RFC5988]
</dt>
<dd>
<cite>
<a href="http://tools.ietf.org/rfc/rfc5988">
Web
Linking
</a>
</cite>
M.
Nottingham.
Editor.
October
2010.
IETF
Standard.
URL:
<a href="http://tools.ietf.org/rfc/rfc5988.txt">
http://tools.ietf.org/rfc/rfc5988.txt
</a>
</dd>
</dl>
</section>
<section id="informative-references">
<h3>
<span class="secno">
<del class="diff-old">E.2
</del>
<ins class="diff-chg">C.2
</ins>
</span>
Informative
references
</h3>
<dl class="bibliography">
<dt id="bib-JSON-LD-API">
<ins class="diff-new">[JSON-LD-API]
</ins></dt><dd><cite><a href="http://json-ld.org/spec/ED/json-ld-api/20120524/"><ins class="diff-new">
The
JSON-LD
API
1.0
</ins></a></cite><ins class="diff-new">
Manu
Sporny,
Gregg
Kellogg,
Dave
Longley,
Markus
Lanthaler,
Editors.
World
Wide
Web
Consortium
(work
in
progress).
24
May
2012.
Editor's
Draft.
This
edition
of
the
JSON-LD
Syntax
specification
is
http://json-ld.org/spec/ED/json-ld-api/20120524/.
The
</ins><a href="http://json-ld.org/spec/latest/json-ld-api/"><ins class="diff-new">
latest
edition
of
the
JSON-LD
Syntax
</ins></a><ins class="diff-new">
is
available
at
http://json-ld.org/spec/latest/json-ld-api/
</ins></dd>
<dt id="bib-RDF-PRIMER">
[RDF-PRIMER]
</dt>
<dd>
Frank
Manola;
Eric
Miller.
<a href="http://www.w3.org/TR/2004/REC-rdf-primer-20040210/">
<cite>
RDF
Primer.
</cite>
</a>
10
February
2004.
W3C
Recommendation.
URL:
<a href="http://www.w3.org/TR/2004/REC-rdf-primer-20040210/">
http://www.w3.org/TR/2004/REC-rdf-primer-20040210/
</a>
</dd>
<dt id="bib-RDF-SPARQL-QUERY">
<ins class="diff-new">[RDF-SPARQL-QUERY]
</ins></dt><dd><ins class="diff-new">
Andy
Seaborne;
Eric
Prud'hommeaux.
</ins><a href="http://www.w3.org/TR/2008/REC-rdf-sparql-query-20080115"><cite><ins class="diff-new">
SPARQL
Query
Language
for
RDF.
</ins></cite></a><ins class="diff-new">
15
January
2008.
W3C
Recommendation.
URL:
</ins><a href="http://www.w3.org/TR/2008/REC-rdf-sparql-query-20080115"><ins class="diff-new">
http://www.w3.org/TR/2008/REC-rdf-sparql-query-20080115
</ins></a></dd>
<dt id="bib-RDFA-CORE">
[RDFA-CORE]
</dt>
<dd>
Shane
McCarron;
et
al.
<a href="http://www.w3.org/TR/2012/REC-rdfa-core-20120607/">
<cite>
RDFa
Core
1.1:
Syntax
and
processing
rules
for
embedding
RDF
through
attributes.
</cite>
</a>
7
June
2012.
W3C
Recommendation.
URL:
<del class="diff-old">http://www.w3.org/TR/rdfa-core/
</del>
<a href="http://www.w3.org/TR/2012/REC-rdfa-core-20120607/">
<ins class="diff-chg">http://www.w3.org/TR/2012/REC-rdfa-core-20120607/
</ins>
</a>
</dd>
<dt id="bib-TURTLE-TR">
[TURTLE-TR]
</dt>
<dd>
Eric
Prud'hommeaux,
Gavin
Carothers.
<cite>
<a href="http://www.w3.org/TR/2011/WD-turtle-20110809/">
Turtle:
Terse
RDF
Triple
Language.
</a>
</cite>
09
August
2011.
W3C
Working
Draft.
URL:
<a href="http://www.w3.org/TR/2011/WD-turtle-20110809/">
http://www.w3.org/TR/2011/WD-turtle-20110809/
</a>
</dd>
</dl>
</section>
</section>
</body>
</html>
